The body of a 13.5 m long male fin whale calf (Balaenoptera physalus, Linnaeus, 1758) was found stranded in Mersin Bay on 13 May 2021. The aim of this study was to present its external examination. The carcass of the juvenile was brought to Mersin University Marine Life Museum and examined extensively. It was observed that the integrity of the body was preserved, while the skin was disintegrated and had localized lesions. It was seen that a significant part of the soft tissues in the head were damaged and the jawbone and cranium remained attached to the body. A complete fracture of the radius and ulna of the left pectoral fin was observed and blood accumulation was noted in the thoracic part due to 10–20 days of decomposition. The left pectoral fin was attached to the body only by skin. The calf’s stomach was empty and it was thought to have been suckled by its mother. The complete breakage of the left pectoral fin could have been caused by a possible ship collision. The accumulation of blood in the thoracic region is probably due to the collapse of
organs inside the body. Lesions and deformations on the skin and loss of soft tissue on the head suggest that the carcass had been adrift at sea for 10 to 20 days. This study provides the first confirmed record of a fin whale stranded in Mersin Bay in Turkish waters.