Superficial thrombophlebitis of the thoracoepigastric veins (also known as Mondor's disease) is an uncommon disorder that typically affects middle-aged women and classically involves the chest wall including the breasts. Only one previously published, non-operative case of the disease, describes how the condition can resemble a strangulated Spigelian hernia. Herein we describe another similar case in which the diagnosis was made intra-operatively. The extremely unusual and similar clinical findings we observed demonstrate that Mondor's disease can occur in the Spigelian hernia belt and cause diagnostic confusion.