To evaluate the incidence of tubulopathies in the long-term follow-up of children post renal transplantation, we reviewed the records of 43 patients from 1987-1996. There were 24 (56%) boys. The age of patients at the time of transplant ranged from 2.7 to 15 years. Eighteen children (78%) had transplantation from cadaver donors (CAD). Thirty-two (74%) patients were transplanted in Saudi Arabia and 11(26%) were transplanted abroad. Significant tubular dysfunction developed in 72% of patients. Renal Tubular Acidosis (RTA) occurred in 23/43 (53%) patients. The patients who received CAD grafts required higher mean dose of bicarbonate and longer duration of therapy compared to living related donors (LRD) recipients ( mean dose of 1.7 Vs 0.5 meq/kg/day and mean duration of 18 Vs 3 (1/2) months, respectively). Hypophosphatemia of various degrees of severity (0.4-0.8 mmol/1) was detected in 12 (28%) patients. Those who received CAD grafts required higher mean dose of phosphate and longer period of therapy than those who received LRD grafts. Hypomagnesemia requiring supplemental magnesium therapy occurred in 4 (9%) patients, all received tacrolimus therapy. In four patients with hypomagnesemia, this was mild and transient. Hypokalemia was found in 5 (11.5%) patients; all had CAD grafts. We conclude that tubulopathies were a frequent complication post renal transplantation in our population. They were more severe in the patients who received CAD grafts. However, the defects were controllable and transient.