Aim: To determine if poor access to healthcare is associated with increased cytomegalovirus (CMV) retinitis risk among patients with HIV with CD4 counts of <100 cells/μL screened in a resource-limited setting. Methods: This is a prospective cross-sectional study. Patients with known HIV and a CD4 count of <100 cells/μL attending an HIV clinic in Chiang Mai, Thailand, completed a standardised questionnaire and underwent dilated fundus examination. Participants without CMV retinitis were invited for repeated examinations every 3 months until their CD4 count exceeded 100 cells/μL. The relationship between various potential risk factors and CMV retinitis was assessed with logistic regression. Results: 103 study participants were enrolled. At enrolment, the mean age was 37.5 (95% CI 35.7 to 39.2) years, 61.2% (95% CI 51.6% to 70.7%) were male and the mean CD4 count was 29.5 (95% CI 25.9 to 33.1) cells/μL. 21 eyes from 16 (15.5%) participants were diagnosed with CMV retinitis. In multivariate analyses, CMV retinitis was significantly associated with lower CD4 count (OR 1.42 per 10-cell decrement, 95% CI 1.05 to 1.93), longer travel time to clinic (OR 3.85 for those with >30-min travel time, 95% CI 1.08 to 13.8) and lower income (OR 1.22 per US$50 less income, 95% CI 1.02 to 1.47). Conclusions: CD4 count, low income and longer travel time to clinic were significant risk factors for CMV retinitis among patients with HIV in a resource-limited setting. These results suggest that reducing blindness from CMV retinitis should focus on increasing accessibility of screening examinations to poor and hard-to-reach patients. ophthalmoscopy, but screening examinations are rarely done in resource-limited settings where the disease burden is highest.18 Given these realities, identifying risk factors for CMV retinitis could help public health officials, HIV doctors and ophthalmologists better understand the populations for which screening examinations would have the highest yield. In a prior study,9 we found that individuals diagnosed with CMV retinitis at a tertiary care centre in Chiang Mai, Thailand, had very advanced disease at the time of diagnosis, with many patients presenting with poor vision due to large retinitis lesions, lesions affecting the macula and optic nerve and retinal detachments. We hypothesised that the advanced state of retinitis was due to a delay in diagnosis, likely related to poor access to healthcare. We subsequently instituted a CMV retinitis screening programme in an HIV clinic in the same city, and collected information about various potential risk factors for CMV retinitis to test the hypothesis that poor access to care plays a role in the development of CMV retinitis.