Pallister-Killian syndrome (PKS; OMIM: # 601803) is a rare sporadic genetic disorder characterized by pigmentary skin changes, distinctive dysmorphology, developmental delay, and mosaicism for tetrasomy of chromosome 12p. The authors report a case of PKS in a 2-y-old boy. He had pigmentary skin changes, characteristic facial features, developmental delay and hearing loss. He had sacral and post-auricular pits in addition, which has not yet been reported. A diagnosis of PKS was suspected on the basis of the patient's clinical features. Skin fibroblast culture was done which showed mosaic tetrasomy of isochromosome 12p consistent with Pallister-Killian syndrome. This case highlights the importance of dysmorphology as a diagnostic tool for recognition and accurate genetic counseling in genetic syndromes.