The objective of the study was to compare socio-economic characteristics of women with illegally induced abortion (IA), legally induced abortion (LA), and women attending antenatal care (AC) by use of a case-referent design. IA women (n= 103) were recruited at the emergency ward at the department of gynaecology, Maputo Central Hospital, LA women (n= 103) at the out-patient gynaecology ward of the same hospital and AC women (n= 100) at a peripheral antenatal care clinic. The variables studied comprised schooling, habitation, household, employment and religious belief. Outcome measures comprised health care expenditures, treatment cost in hospital and individual cost for the woman. Women with IA, in relation to women with LA, differed significantly in the following respects. They were younger and more likely to be single (OR 2. 16), more often educated below secondary school level (OR 5. 77), more often living in shanty towns (OR 2.77) and in households with more numerous members (OR 2. 38). They were more often housewives or street saleswomen and less often public employees (OR 3.49). Their mean individual salary was lower (P≤ 0.02) and so was the total salary of all household members (P≤ 0.0001). They were less often Catholics (OR 0.41). The health care expenditure of the hospital was significantly higher for illegal than for legal abortion (P≤ 0.0001). Access to safe legal abortion, being less costly to society, was, however, restricted because of the significantly higher intervention cost than an illegal abortion for the individual woman (P≤ 0.0001). AC women were found to be similar to LA women in several respects but the pattern was not consistent throughout. It is concluded that women seeking IA in Maputo belong to a poor segment of the population and that safe LA is more expensive for the individual woman than an unsafe illegal one. The wider implications of the findings for policy and practise are addressed.