We evaluated the effects on bone mineral density (BMD) of a 12-month treatment with goserelin depot, a gonadotropin-releasing hormone agonist, in a group of women with symptomatic uterine myomas requiring hysterectomy. Sixteen women, mean age 45.6 +/- 5.0, reporting menorrhagia associated with uterine myomas, candidates for hysterectomy, were scheduled to be treated with goserelin depot for 12 months. BMD was measured at the vertebral (L2-L4) and proximal femur level (femoral neck and trochanter) at the start of therapy and 6, 12, and 18 months later using dual energy X-ray absorptiometry (Hologic QDR 1000/W). The patients were followed for a minimum of 6 months after the end of treatment. Thirteen of the 16 women enrolled completed the treatment and three suspended it after 5, 6, and 7 months, respectively, because of side effects (hot flashes, insomnia, depression). Of the 13 women who completed the treatment, three underwent hysterectomy because of myoma regrowth and the recurrence of symptoms 3-18 months later; four reached the menopause 5-16 months later, and six were all menstruating normally with a follow-up varying from 6 to 18 months. After 12 months of therapy we observed a bone loss at vertebral, femoral neck, and trochanter of 4.4% (P < 0.05 versus baseline; P = not significant versus 6 months), 7.5% (P < 0.01 versus baseline, P < 0.01 versus 6 months), and 7.6% (P < 0.001 versus baseline, P < 0.05 versus 6 months), respectively. Six months later, BMD increased slightly and not significantly at different sites (0.9% at the spine, and 0.3% at femoral neck, and 1.1% at trochanter). A 12-month treatment with goserelin may avoid the need for hysterectomy in women over 40 with symptomatic myomas. However, this therapy is associated with a marked bone loss which is not significantly reversed at its suspension.