Propylea dissecta (Mulsant) (Coleoptera: Coccinellidae) is one of the most promising ladybird beetle against many sucking pests. Predation rates, developmental biology, life table, and field assessment of this ladybird were examined against mustard aphid, Lipaphis erysimi (Kalt.) (Hemiptera: Aphididae), on broccoli. Data on the life history were collected at 23 ± 1°C and 70 ± 1% RH and were evaluated using the two-sex, age-stage life table. Results showed that the two-sex, age-stage life table-based net reproductive rate (R0) was 11.264 ± 6.197 offspring. The adult females lived longer (33.8 ± 2.356 d) than the adult males (32.2 ± 0.841 d). The fourth instar consumed most of L. erysimi (113.97 ± 5.76) compared to the other larval stages of the predator. Male (1,821) and female (2,673) consumed more aphids than larvae. The net consumption rate was 741.78 ± 89.91 aphids. Other aphidophagous predators such as Coccinella septempunctata L., Micraspis discolor (F.), Coccinella transversalis (F.), and syrphid (Diptera: Syrphidae) were also noted in broccoli. Our research showed that inoculative release of 150 or 200 adults per 1,000 m2 for two times on broccoli achieved a significant decrease in aphids L. erysimi and Brevicoryne brassicae L. (Hemiptera: Aphididae) (>95%). The release rate of 150 adults per 1,000 m2 for two times may, therefore, be recommended to manage the aphid population on broccoli.