Autoimmune myasthenia gravis is a disorder with a complex pathomechanism in which sex hormones, in particular oestrogen, have long been considered to play a role. Here we report the result of a case-control study which evaluated the association of two oestrogen receptor alpha gene polymorphisms with myasthenia gravis in Caucasian patients. PvuII (rs2234693) and XbaI (rs9340799) restriction fragment polymorphisms of the oestrogen receptor alpha gene were analyzed in 113 female myasthenia patients and 184 female controls. Distribution of these polymorphisms was compared with PCR-RFLP. Patients were divided into groups according to their oestrogen receptoralpha genotypes, and acetylcholine receptor antibody status and age of onset were compared between the groups. We found no significant difference between any of the groups implying that these two polymorphisms probably do not play a role in the pathomechanism of myasthenia gravis in Caucasian women.