Purpose: Identify prevalence of Retinopathy of prematurity (ROP) at neonatal department of National hospital of Obstetrics and Gynaecology from 1st Jan, 2003 - 31st Dee, 2005 and find out the relationship between ROP and birth weight (BW) and gestation age (GA). Patients and method: 590 pretenn babies less than or equal 2000g BW and 35 weeks GA was included. All babies were screened ROP at 3-4 weeks after birth. Results: 223/590 babies had ROP, account for 37.8 percent. Among them 142 babies needed treatment, account for 24.1 percent. Rate of babies who need treatment in the group of BW less than 1000g and GA less than 28 weeks is 77.8 percent and 100 percent respectively
from 1000 -1500g and from 28-31weeks is 30.5 percent and 40,7 percent
1500g and 31 weeks is 11.9 percent and 11.5 percent. Conclusion: Prevalence of ROP was 37.8 percent and 24.1 percent patients needed treatment. ROP has close relationship with BW and GA.