An infection of sheepshead minnows (Cyprinodon variegatus) by myxosporidia (Myxobolus lintoni) was discovered in a brackish pond on Assateague Island, Virginia. Twenty-seven of the 550 (5%) captured sheepshead minnows exhibited epidermal lesions: white, raised, irregular tissue masses. There were no epidermal lesions noted in any of the four other fish species occurring in the pond. The apparent outcome in this episode of myxosporidian infection was death of the host fish.