The aim of this study was to find the prevalence of filarial nematodes in dogs in Istanbul, Turkey and identify the species by using naphtol AS-TR phosphatase technique. A total of 286 blood samples were taken from the dogs of different areas of Istanbul, Turkey, between March 1999 and November 2002. The Knott technique was used to detect the microfilariae in blood. Two dogs were found to be positive for microfilariae. The positive blood samples were stained by naphtol AS-TR phosphatase for differentiation. The microfilariae were identified as Dipetalonema recondition. In this study, differentiation of canine microfilaria based on somatic distribution of acid phosphatase activity was performed for the first time and according to these results D. reconditum was reported for the first time from Turkey.