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During routine dissection, variation of sciatic nerve was discovered bilaterally. Sciatic nerve emerged from the pelvis through greater sciatic foramen. On both sides, it divided into common peroneal nerve and tibial nerve. Common peroneal nerve pierced the piriformis muscle with resultant splitting of the muscle into two parts. Tibial nerve emerged at the lower border of muscle, thus two divisions of sciatic nerve were separated by the inferior belly of the piriformis muscle. On the left side common peroneal nerve from its medial edge gave branches which innervated gluteus maximus muscle from its deeper aspect. On the right side both common peroneal nerve and tibial nerve gave branches to gluteus maximus muscle. In addition, bilaterally gluteus maximus was innervated by inferior gluteal nerve.