OBJECTIVE : Many Sub-Saharan Africa countries have witnessed rapid scale-up of HIV treatment and care services in recent years. However, there is increasing evidence suggestive of poor quality of services. In this study, we examined clients' satisfaction with quality of HIV treatment and care services in Nigeria. METHODS : This was a cross-sectional survey of people living with HIV (PLHIV) receiving HIV treatment and care services. METHODS : The study included 1212 PLHIV receiving HIV treatment and care in 96 health facilities across 12 states. We collected data on clients' satisfaction with four quality domains (confidentiality, staff attitude, physical structure, and perceived improved health) and the overall quality of care, sociodemographic characteristics, type of facility, distance to facility, and time spent at facility. A logistic regression analysis was conducted with clients' satisfaction with the overall quality of care as the dependent variable. RESULTS : About 90% of the respondents were satisfied with the overall quality of care. Women, rural dwellers, and Muslims, public (government-owned) healthcare facility users, those unsatisfied with confidentiality, and those unsatisfied with staff attitude had statistically significant lower odds of being satisfied with the overall quality of care. After adjusting for sociodemographic characteristics and the type of facility, confidentiality (adjusted odds ratio [AOR] = 0.1, 95% confidence interval [CI] = 0.01-0.81, P = 0.031) and staff attitude (AOR = 0.24, 95% CI = 0.09-0.67, P = 0.006) remained statistically significant. CONCLUSIONS : Clients' satisfaction with the quality of HIV treatment and care services at health facilities in Nigeria appears high. HIV service provision should be in line with standard ethical principles and more patient centered and responsive to sociodemographic characteristics of PLHIV.