According to case and control studies we determine the prevalence of anticardiolipin antibodies (ACA) and autoimmune phenomena in 23 women with recurrent abortions (two or more) without apparent cause after study, using as pattern a sample of 86 patients belonging to different subgroups: 21 women with only one abortion, 15 with toxemia, 30 healthy pregnants and 20 healthy non-pregnants. We found that 6 (26%) of the cases with recurrent abortions showed high ACA-IgG versus 6 (7%) of the control group (p = 0.009), with an odds ratio (OR) of 4.7 (Confidence Interval [CI] 95%, 1.4-15). We didn't find a relation with ACA-IgM, OR or 2.2 (CI 95%, 0.72-6.50; p = 0.160). Our patients only showed as manifestation of antiphospholipid antibodies syndrome, recurrent abortions, finding neither association with thrombotic phenomena, nor thrombocytopenia. They didn't show either clinical or analytical manifestations of autoimmune disease. We concluded that the ACA-IgG can be associated to the fetal loss in these kind of patients.