Assumed mutual antagonism of T-helper cell (Th)1 and Th2 diseases suggests that the prevalence of atopy should be decreased in rheumatoid arthritis (RA). We tried to determine that prevalence. Sixty-two patients with RA and 61 with osteoarthritis (control group) were included in the study. A questionnaire was used concerning mainly the symptoms of atopy. Skin prick tests, pulmonary function tests, chest X-rays, immunoglobulin E levels, and eosinophil counts were obtained. The prevalences of asthma, hay fever, and eczema in the RA group were 3.2%, 14.5%, and 1.6%, respectively. In the control group, they were 6.5%, 22%, and 6.5%, respectively. There was no significant difference between groups. There was also no significant difference between immunoglobulin E levels. Eosinophil counts were higher in the control group, however these values were within the normal range. Skin prick tests were obtained in seven RA patients, and eight controls revealed increased positivity. The prevalence of atopy in rheumatoid arthritis was not different from that in the general population. Our study results cannot support the concept of Th1/Th2 mutual antagonism.