The gastrocnemius muscle is rarely considered today as a musculocutaneous flap. Yet, the posterior calf skin by itself can still be used to advantage as a source of local or perhaps free flaps. Fascial perforators in this region were reexamined in an anatomic study in 10 fresh cadaveric specimens to investigate the possibility of a gastrocnemius muscle perforator-based flap. At least two substantive perforators were found in all limbs, and there was always one overlying the medial gastrocnemius muscle (overall mean, 4.0 +/- 1.8 perforators; range, 2-7 perforators). The origin of these perforators in any given specimen was most commonly as a secondary branch from the medial or lateral sural arteries alone (60%), from the median sural artery as a direct cutaneous branch alone (10%), or from either of the muscle pedicles and/or the median sural artery (30%). Thus, in 90% of limbs, the potential for elevating a gastrocnemius perforator-based flap exists without the need for any muscle sacrifice. Otherwise, a more traditional posterior calf fasciocutaneous flap was possible. Other deeper intramuscular collaterals were also identified so that sequential use of the muscle as a separate flap does not seem to be compromised.