Objective To determine risk factors associated with infection and traumatic lacerations and to see if a relationship exists between infection and time to wound closure after injury.

Methods Consecutive patients presenting with traumatic lacerations at three diverse emergency departments were prospectively enrolled and 27 variables were collected at the time of treatment. Patients were followed for 30 days to determine the development of a wound infection and desire for scar revision.

Results 2663 patients completed follow-up and 69 (2.6%, 95% CI 2.0% to 3.3%) developed infection. Infected wounds were more likely to receive a worse cosmetic rating and more likely to be considered for scar revision (RR 2.6, 95% CI 1.7 to 3.9). People with diabetes (RR 2.70, 95% CI 1.1 to 6.5), lower extremity lacerations (RR 4.1, 95% CI 2.5 to 6.8), contaminated lacerations (RR 2.0, 95% CI 1.2  to 3.4) and lacerations greater than 5 cm (RR 2.9, 95% CI 1.6 to 5.2) were more likely to develop an infection. There were no differences in the infection rates for lacerations closed before 3% (95% CI 2.3% to 3.8%) or after 1.2% (95% CI 0.03% to 6.4%) 12 h.

Conclusions Diabetes, wound contamination, length greater than 5 cm and location on the lower extremity are important risk factors for wound infection. Time from injury to wound closure is not as important as previously thought. Improvements in irrigation and decontamination over the past 30 years may have led to this change in outcome.