A total of 20 children with benign transient hyperphosphatasemia were prospectively evaluated with no additional investigations recommended except repeat serologic evaluation in 2-3 months. The average age of our patients was 2.5 years (range 1 year 2 months-5 years 10 months). The serum levels of alkaline phosphatase averaged 2383 IU/L (range 1013-5700 IU/L). Levels returned to normal within several months. This condition should be recognized by the clinician in order not to put patients through lengthy, expensive and unnecessary investigations.