Reflex sympathetic dystrophy syndrome (RSDS), which probably has a multifactorial etiology, may appear after kidney transplantation. Its clinical manifestations include severe periarticular pain with inflammatory signs, especially in knees and ankles, causing functional disability. Symptoms develop during the first 3 months after transplantation and usually disappear 3 to 6 months later without sequelae. In renal transplant recipients it has previously been related to immunosuppressive treatment with cyclosporine. Therefore we had suggested that introducing tacrolimus could be a therapeutic option. We now present four cases of RSDS in kidney transplant recipients treated with tacrolimus. All but one patient were receiving tacrolimus monotherapy, excluding other drugs that might have been involved to cause the syndrome. It is also interesting that one of our cases develop RSDS long after transplantation when immunosuppressive treatment was changed. Symptoms correlated with an increase in alkaline phosphatase and with bone scintigraphy findings. All patients recovered without sequels 3 to 6 months afterward. In conclusion, RSDS is a relevant osteoarticular complication in patients receiving either anticalcineurinic drug (CyA or tacrolimus), even under monotherapy or with a low steroid dose.