This cross-sectional population-based study in a peripheral low-income community in São Paulo, Brazil, aimed to estimate the prevalence of unsafe abortion and identify the socio-demographic characteristics associated with it and its morbidity. The article discusses the study's results, based on univariate and multiple multinomial logistic regression analyses. The final regression models included: age at first intercourse < 16 years (OR = 4.80); > 2 sex partners in the previous year (OR = 3.63); more live born children than the woman's self-reported ideal number (OR = 3.09); acceptance of the abortion due to insufficient economic conditions (OR = 4.07); black ethnicity/color (OR = 2.67); and low schooling (OR = 2.46), all with p < 0.05. The discussion used an approach to social determinants of health based on the concept and model adopted by the WHO and the health inequities caused by such determinants in the occurrence of unsafe abortion. According to the findings, unsafe abortion and socio-demographic characteristics are influenced by the social determinants of health described in the study, generating various levels of health inequities in this low-income population.