The ovipositional status of field populations of adult stable flies,Stomoxys calcitrans(L.), in cattle feedlots was investigated for 3 yr in southeast Nebraska. The proportions of female flies in each of three ovipositional stages (nulliparous, uniparous, and biparous) collected by two sampling methods (a stanchioned-calf technique and Alsynite fiberglass traps) at three times of day at two cattle feedlots were compared. In 2 of the 3 yr of the study, location (Feedlots A, B, or C), time of sampling (0800, 1100, and 1400 hours), and method of collection did not affect significantly the proportions of female stable flies in each ovipositional stage. During the 3 yr of the study, nulliparity was the predominant ovipositional stage. At the time of population peaks of adult stable flies, the majority of female stable flies were nulliparous, which indicates that the population peaks are caused by young flies that had recently emerged. More than 97.0% of the female flies collected during this study had immature eggs. We concluded that both methods sampled the same population of female stable flies: each method has strengths for different types of ecological studies. Also, we feel that increasing stable fly populations at any feedlot develop on site and are not a result of immigration. Furthermore, at beef cattle feedlots, most adult female stable flies do not live much beyond one egg cycle.