To identify difficulties in accessing health services by the elderly in the city of São Paulo/Brazil and the contributory factors that reflect inequalities. This is a cross-sectional study that used data from the Health, Well-being and Aging Study (SABE). The population is composed of elderly ≥ 60 years old, of both sexes, living in the urban area of São Paulo. For this analysis, we used data from the 2015 cohort of the SABE study, containing a sample of 1,221 individuals. The proportions of access difficulty and, through logistic regression, the associated factors were verified, based on Andersen's Behavioral Model, which considers factors of predisposition, enabling and need as individual determinants of access to health care. It was observed that 37.0% of the elderly reported difficulty accessing health services when they needed it. This difficulty was greatest among females (42.3%), aged 60 to 69 years (40.9%), black race/color (58.8%), illiterate (44.5%), single/separated/divorced (44.3%), with income slower than one salary minimum (46.8%), without health insurance (51.9%), with poor/very poor self-assessment of health (54.7%), with multimorbidity (40.1%), frail (47.2%) and among those who used polypharmacy (40.8%). After multivariate analysis, in the final model, there was a positive association between difficulty of access and predisposing factors (female gender, age group 60 to 69 years, black race/color, illiterate), enabling factors (possession of health insurance) and need factors (regular and poor/very poor self-assessment of health and pre-fragility and frailty condition). The presence of difficulty in access associated with predisposing, enabling and need factors reflect the existence of inequalities caused by barriers that point to weaknesses in the organization of services. The identification of these barriers that hinder access highlights important points that can have an impact on the equity and resolution of care.