AIM: To evaluate the long-term effects of pattern scan laser (PASCAL) pan-retinal photocoagulation (PRP) on diabetic retinopathy (DR) in Chinese patients. METHODS: In this retrospective study, we evaluated clinical data of 29 patients (53 eyes) with severe non-proliferative DR (SNPDR) or proliferative DR (PDR) who received PRP and follow-up at our hospital from 2008 to 2013. Sixteen patients (29 eyes) received PASCAL PRP and 13 patients (24 eyes) received 100-ms conventional laser PRP. RESULTS: After long-term follow-up (mean, min-max days: 719.8, 290-1666 for PASCAL PRP vs 743.5, 240-1348 for conventional PRP, P=0.569), patients receiving PASCAL PRP required fewer photocoagulation sessions than the conventional PRP group (2.6±1.0 vs 3.9±0.9, P<0.01). Best corrected visual acuity (BCVA) was reduced slightly in PASCAL PRP group while reduced significantly in conventional PRP group. At last visit, 24 eyes in the PASCAL group (88.9%) and 21 eyes in the conventional group (91.7%) were improved or stable. Two eyes in PASCAL PRP group (7.4%) and 3 eyes in the conventional PRP group (12.5%) developed vitreous hemorrhage or vitreous fibrovascular proliferation. CONCLUSION: PASCAL PRP is as effective and may be more conducive to maintaining visual acuity with less treatment sessions for DR treatment compared to conventional laser PRP.