Gizzard shad Dorosoma cepedianum, threadfin shad D. petenense, hybrid gizzard shad x threadfin shad, and alewives Alosa pseudoharengus were collected from Cherokee, Dale Hollow, and Old Hickory reservoirs, Tennessee, from January 1984 through December 1984. Samples were analyzed for proximate composition (moisture, ash, protein, and fat) and gross energy content. Overall ranges of nutrients for all collections were determined: Moisture, 69.7–84.9%; ash, 12.0–32.5%; protein, 45.4–79.1%; fat, 3.3–31.5%; and gross energy, 3.92–6.06 kcal˙g−1. Changes in protein, ash, and moisture percentages within an age-class of a species were primarily the result of changes in fat percentage. In general, fat content increased through summer, peaked during fall, and declined during winter. Seasonal variations in reproductive condition, as well as differences in age and sex, were causes of variations in body composition within a species. Proximate composition and gross energy content of the clupeids examined were similar; however, young-of-the-year and adult alewives exhibited the highest individual gross energy values in their respective age-classes.