BACKGROUND: To detect the possible etiological factors in the origin of isolated congenital cataracts. METHOD: The data set of the Hungarian Case-Control Surveillance of Congenital Abnormalities, 1980-2002, contained 111 cases with isolated congenital cataract and their 111 matched control pairs without defect, 22744 patient controls with other non-ocular abnormalities and 37837 population controls without any defects. Exposure data and family history were based on (i) medical records, (ii) retrospective maternal information and (iii) information obtained by regional nurses at home visit of nonrespondent families. RESULTS: Positive family history indicated autosomal dominant origin in 9,9% of the cases. Rubella infections occurred more frequently in case mothers than in control mothers before the vaccination against rubella virus. A higher prevalence of influenza/common cold (55.9% in the case and 18.5% in the population control group, adjusted OR with 95% CI: 5.8, 4.0-8.4 and 21.7% in the malformation control group: 4.7, 3.2-6.9) and acute infectious diseases of respiratory system (26.1% in the case and 9.1% in the population control group: 3.8, 2.5-5.8 and 9.3% in the malformation control group: 3.4, 2.2-5.3) related with fever was found during the pregnancy of the case mothers. In addition the higher risk of isolated congenital cataract was prevented by antifever therapy. CONCLUSIONS: Some part of isolated congenital cataract is preventable by rubella vaccination and probably by influenza vaccination in the epidemic period, in addition it is worth using an effective antifever therapy of fever related respiratory diseases to restrict the teratogenic risk of fever.