Personal Injury

What Is Negligence Per Se and How Does It Apply in Oregon?

By June 25, 2026August 4th, 2026No Comments

Regardless of whether you have been injured in an automobile accident on I-5 or in a slip-and-fall accident at Cascade Station, you are probably dealing with unexpected medical bills, lost wages, and other related damages. In Oregon, the negligence per se doctrine acts as a “procedural shortcut” in personal injury lawsuits. 

The negligence per se doctrine allows the plaintiff to prove that the defendant was negligent by showing that they violated a safety regulation or statute. Without this legal precedent, plaintiffs would have to establish that the defendant breached a “reasonable duty of care,” which is the standard in most personal injury claims. 

What Is Negligence Per Se and Its Elements in Oregon

In Oregon, the negligence per se doctrine provides that a person may be automatically considered negligent if they violated a safety regulation or statute intended to protect others from harm and the violation caused the plaintiff’s injury. The Latin term “per se” means “in itself” or “by itself,” indicating that a statutory violation can establish negligence.

A plaintiff in an injury case must prove four legal elements:

  • The defendant violated a regulation, statute, or ordinance.
  • The statute was intended to protect a class of people that includes the plaintiff. Example: The law requiring drivers to stop at red lights is intended to protect motor vehicle occupants and pedestrians.
  • The statute was intended to prevent the type of injury the plaintiff experienced. Example: A law prohibiting distracted driving is intended to prevent crashes and injuries such as those suffered by the plaintiff.
  • The statutory violation was the cause of, or a substantial factor contributing to, the plaintiff’s injury. Example: A driver’s failure to stop at a red light caused a crash that injured the plaintiff, making the violation a contributing factor in the harm they suffered. 

Even so, under Oregon law, if a defendant violates a safety law without a valid excuse, the violation may be used as evidence of negligence. But Oregon law allows a defendant to challenge or explain the violation to try to prove they were not negligent. 

How It Differs from Ordinary Negligence with Common Oregon Examples

In most negligence cases, the plaintiff must establish that they were owed a duty of care and that the defendant did not meet the legal standard. In a case involving negligence per se, the statute defines the duty of care, and any violation constitutes a breach. Even so, the plaintiff must still prove causation and that they suffered actual damages. 

Negligence per se does not guarantee that a plaintiff will prevail. Instead, it simplifies the legal elements required to prove the breach but does not eliminate the other requirements. 

Traffic Law Violations

Common traffic law violations involving negligence per se include:

Building Code and Property Violations

Some of the most common building code and property violations include:

  • Failure to maintain safe premises in violation of Portland building codes.
  • Violation of the Oregon Structural Specialty Code.
  • Absence of required lighting, handrails, or fire exits.

Product Safety Violations

Negligence per se is often raised in cases involving the manufacture or sale of products that violate federal safety standards, including FDA requirements or CPSC regulations.

Alcohol Service Violations

Negligence per se often plays a factor in cases where alcohol was served to a visibly intoxicated individual. Doing so violates the state’s dram shop statutes (ORS 471.565).

Defenses to Negligence Per Se in Oregon

Under Oregon law, negligence per se creates a rebuttable presumption, allowing the defendant to offer defenses:

Excused Violation

There are specific instances where a violation of negligence can be excused:

  • The defendant could not reasonably comply despite making good-faith efforts.
  • The defendant was unaware of the need to comply.
  • The violation occurred due to an emergency.
  • Following the law would have created a greater risk of harm

No Causal Connection

Negligence per se may not apply if the violation did not cause the plaintiff’s injury. Example: The defendant was speeding, but the plaintiff’s illegal turn caused the accident.

Contributory/Comparative Negligence

Oregon also follows a modified comparative negligence doctrine (ORS 31.600), meaning the plaintiff’s negligence can reduce or bar recovery if it is found to be 51% or more at fault. Even so, a finding of negligence per se by the defendant does not eliminate the need to evaluate whether the plaintiff also contributed to the accident. 

How Negligence Per Se Strengthens Your Personal Injury Claim

Whether you have been injured by a drunk driver who was served too much alcohol on N. Mississippi Avenue or been injured due to a building code violation in the Old Town area, negligence per se can strengthen your personal injury claim. 

Some of the key takeaways in the negligence per se doctrine include:

  • Simplifies the burden of proof and does not require you to provide expert testimony to establish a duty of care.
  • Provides your attorney with greater leverage when negotiating with the insurance company. 
  • Makes it more difficult for the defendant to argue that they acted as a reasonable person would under the same circumstances.
  • Gives greater credence to cases where the defendant received a traffic citation or was convicted of a violation. 

It is worth emphasizing that a criminal conviction for a violation, such as a DUII conviction, is admissible in a personal injury case. 

If you have been injured in an accident in Multnomah County and have questions about how Oregon’s negligence per se doctrine may apply, contact Tillmann Law today at (855) 503-5035 to schedule a free consultation.