The aim of this randomised controlled trial was to compare efficacy and safety of two doses of low molecular weight heparin (enoxaparin) in pregnant women with a history of recurrent abortion secondary to antiphospholipid syndrome. A total of 60 women with a minimum of three consecutive abortions before 10 weeks' gestation and positive lupus anticoagulant and/or anticardiolipin antibodies on at least two occasions at least 12 weeks apart were randomised into two groups based on computer generated randomisation list concealed in opaque envelopes. Pregnant women were treated with enoxaparin 40 mg plus low dose aspirin (LDA) (n = 30) or enoxaparin 20 mg plus LDA (n = 30). The live birth rate was 76.67% in enoxaparin 40 mg group and 70% in enoxaparin 20 mg group (p value = 0.559). There were no significant differences between both groups with respect to neonatal outcome, obstetric and maternal complications during pregnancy or puerperium. No cases of severe bleeding, thrombocytopenia or spontaneous fractures were reported in both groups.