The aim of this study was to assess neonatal pain scores during laser treatment for retinopathy of prematurity (ROP) under sub-tenon anaesthetic with oral or rectal sedation. Sixty-two babies were included who have had ROP laser treatment over a seven year period. Pain scores were assessed using the Neonatal Pain Agitation and Sedation Scale (N-PASS) every 10 minutes during laser treatment. The outcome and requirement for re-treatment in this group was compared with that in the intravenous sedation group. Pain scores were available in 19 of the 27 babies treated under sub-tenon anaesthesia. The mean pain score during treatment was 2.7 (SD±1.7, range 0.5-6.2). There was no statistically significant correlation between the mean pain score and duration of treatment, number of laser burns, or post-menstrual age of the baby at the time of treatment. Both treatments were equally successful irrespective of the sedation method. The mean pain scores during laser treatment under sub-tenon anaesthesia were lower than those previously reported during ROP screening or heel-stick procedure. This study supports that sub-tenon anaesthesia with oral or rectal sedation provides sufficient pain control for laser treatment for ROP without the need or risks of intravenous sedation and intubation.