| Family size is reduced among patients with rheumatic diseases. The causes for the low number of children are multifactorial and include impaired sexual function, decreased gonadal function, pregnancy loss, therapy and personal choices. Sexuality contributes to quality of life in patients with rheumatic disease, but is often ignored by health professionals. Both disease-related factors and psychological responses to chronic disease can impair sexual functioning. Toxic effects of anti-inflammatory and immunosuppressive drugs can induce transient or permanent gonadal failure in women and men. Furthermore, permanent infertility can be a consequence of treatment with cyclophosphamide, whereas transient infertility can be caused by NSAIDs in women and sulfasalazine in men. These adverse effects must be communicated to the patients, and measures to preserve fertility should be initiated before the start of gonadotoxic therapy. Management of patients of both genders should include regular family planning, effective treatment of high disease activity, sexual counselling, and, if necessary, infertility treatment.