This paper documents an unusual case of a stress fracture of the ninth rib in an elite oarsman. A 25-year-old male presented with a 3-day history of right-sided chest pain aggravated by deep inspiration and movements simulating rowing. The athlete was treated initially as having a soft tissue injury; however, a technetium-99 bone scan confirmed the diagnosis. Routine radiographs of the ribs were negative. The pain and symptoms were confined to the anatomical area of the fracture along the anterolateral portion of the rib where the serratus anterior muscle originates. An analysis of the stroke mechanics involved in rowing implicated the serratus anterior muscle as being a major contributor to the repetitive stress that resulted in the injury. The primary etiological factor was errors in the training program. The athlete responded to simple conservative measures and was able to return to competitive rowing in 1 month's time.