We conducted a randomized, controlled study to assess the need for hydroxychloroquine (HCQ) during lupus pregnancy and to assess safety. Twenty consecutive pregnant patients with similar characteristics were enrolled. The HCQ group included eight patients with systemic lupus erythematosus (SLE) and two with discoid lupus erythematosus (DLE). The placebo (PL) group included nine patients with SLE and one with DLE. The HCQ group had no flare-ups. SLEPDAI scores were similar at study entry, and at conclusion the placebo group had significantly higher scores. One patient had improvement of skin lesions and another of arthritis, allowing a decrease of prednisone dose. There were no retinal effects. Three patients in the PL group flared up, two with skin rashes, one also with arthritis and uveitis, and one (previously in remission on HCQ) with hemolytic anemia, polyserositis and anti-dsDNA antibody. Toxemia was diagnosed in only three patients in the PL group (one fetal death). Comparing prednisone dosage change, we noted a decrease in the HCQ and an increase in the PL group. Delivery age and Apgar scores were higher in the HCQ group. Neonatal examination did not reveal congenital abnormalities, nor did a neuro-ophthalmological and auditory evaluation at 1.5-3 y of age. In spite of the small number of patients studied, we noted beneficial effects of HCQ during lupus pregnancy, as measured by SLEPDAI and decrease in prednisone dose with no detriment to patients' health.