The efficacy and side-effects of Deca-Durabolin (DD) were tested, in a double blind fashion, in twenty female primary Sjögren's syndrome (1 degree SS) patients. Ten randomly assigned patients received DD (100 mg IM bi-weekly) for six months, and ten others placebo, for the same period. Analysis of the results revealed that the DD-treated patients showed a moderate improvement of subjective xerostomia, a significant decrease of the erythrocyte sedimentation rate (ESR), and an overall improvement of their feeling of well-being, -judged by themselves and the investigator subjectively-, when compared with the placebo group. All the sicca objective parameters (results of Schirmer's I test, slit lamp eye examination after rose bengal staining, stimulated parotid flow rate measurements and labial minor salivary gland histopathology) were not significantly altered in either group. The clinical side-effects were the expected ones, i.e. hirsutism, hoarseness and an increase in libido, more pronounced in the DD-treated group. At the end of the study, one DD-treated patient, developed a diffuse well-differentiated B-lymphocytic lymphoma, which regressed spontaneously three months later.