Aims: To examine the predictive value of serum lipids on the need for panretinal photocoagulation (PRP) treatment in a long-term follow-up of a cohort of Danish type 1 diabetic patients. Methods: A total of 243 type 1 diabetic patients were included from a population-based cohort. Of these, 25 patients (10.3%) were excluded due to proliferative diabetic retinopathy (PDR) at baseline. The remaining 218 patients were followed from January 1993 to November 2006. Serum levels of lipids were collected at baseline. PRP treatment was considered as indicative of PDR during follow-up, and the date of PRP was documented from the Danish National Patients Registry. Results: At baseline, the median age and duration of diabetes were 45.9 years (range 23.9-78.4 years) and 30 years (range 20-72 years), respectively. In the crude analysis, serum triglyceride was associated with incident PRP. However, after adjustments for baseline age, sex, duration of diabetes and HbA1c, this was no longer statistically significant, although a clear trend was found (hazard ratio 1.40, 95% confidence interval 0.97-2.03, p=0.07, for each 1mmol/L increase in serum triglyceride). Total cholesterol, HDL cholesterol and LDL cholesterol were not associated with a higher risk of incident PRP. Conclusions: In a 13-year follow-up of a population-based cohort of long-term type 1 diabetic patients, there was a trend of an association between serum triglyceride and subsequent need of PRP treatment, which was used as a surrogate endpoint of PDR. This identifies triglycerides as a potential risk factor of PDR in type 1 diabetes.