Calf muscle tears are relatively common. They can be identified well as incidental findings using duplex sonography when performing a lower extremity venous Doppler exam. A case is presented of a 43-year-old male patient who underwent a sonogram to diagnose deep vein thrombosis. The exam results demonstrated patent and compressible common femoral, femoral, popliteal, and calf veins without evidence of deep vein thrombosis. As the sonographer was documenting the popliteal fossa, a complex fluid-filled structure within the left gastrocnemius muscle was identified. The diagnosis was reported as a gastrocnemius muscle tear. This case demonstrates a fairly common incidental finding, gastrocnemius muscle tear, when performing a venous Doppler exam.