Age-grouping techniques were applied to 15 face fly (Musca autumnalisDe Geer) populations, representing two locations in central Iowa, three locations in Minnesota, and one location in northern California. A total of 11,839 females was graded by age. Up to 13 gonotrophic (age) groups were recognized. Age distributions of all populations were compared. Bias due to sampling methods and sampling location was evaluated. Flies on sticky traps suggested younger population age structures than did flies obtained with sweep nets. Suitability of the data for achieving a synthetic, vertical life table was determined. Survival functions were fitted to the gonotrophic distributions. Average daily survival probabilities varied from 0.87 in Minnesota to 0.95 in Iowa when estimates were made from proportions parous. The survival distributions were remarkably uniform among years and locations. The proportions multiparous gave estimates of lesser survival rates, suggesting that this age group was not accurately classified or that risk of mortality increased with age.