After orthotopic liver transplantation (OLT) bone mass rapidly declines and vertebral fracture rate increases. We studied bone loss and parameters of bone turnover in 53 consecutive patients. In an attempt to reduce bone loss the patients were prophylactically treated with cyclical etidronate in addition to daily 1 alpha-hydroxyvitamin D3 and calcium. During the first 3 months after transplantation median lumbar spinal bone mineral density (BMD) decreased 4.5%; subsequently no significant changes occurred. Median hip BMD continued to fall during the first post-transplantation year and deteriorated 7% over the whole study period. New vertebral fractures were seen in 25% of the patients, which is not lower than previously reported rates in patients not receiving cyclical etidronate. Parathyroid hormone levels increased after OLT (p = 0.01), but remained within normal ranges. Urinary hydroxyproline levels were increased and normalized in the second half-year after OLT. Elevated fasting calciuria increased further after OLT. 1,25-Dihydroxy-vitamin D3 levels were lowered pre-OLT (25 vs 66 pmol/ 1, p < 0.001) and normalized at 3 months after OLT. Serum osteocalcin concentrations remained unchanged and were reduced compared with levels in healthy controls. In summary, increased bone resorption occurs after OLT with persistent decreased bone formation, leading to vertebral fracture in 25% of patients. Etidronate, 1 alpha-calcidol and calcium treatment did not prevent bone loss.