Laboratory-reared Pacific white shrimp (Penaeus vannamei) postlarvae were released into the Huizache-Caimanero and Cerritos lagoon system (Sinaloa, Mexico) using a stock enhancement approach to improve production and preserve the wild spawning stock. Fifty-two point three million postlarvae were sown, and the system was monitored between June 28 and November 29, 2019. A total of 3844 shrimp ranging from 27 to 170 mm in total length (TL) and 0.2 to 41.2 g in total weight were obtained. Individuals were classified in 5-mm size classes to estimate the length at first maturity (TL50%: 110 mm) as a proxy of the length (age) at which they become part of the breeding stock. The associated relative age (based on the mean postlarvae length) was 80 days, with most of the sampled specimens ranging from 60 to 100 days in age. Molecular analysis of genomic expression was performed to compare the genetic profiles of samples obtained in June 2019, October 2019, and 2012 (reference) and detect possible genetic admixture between hatchery and wild specimens. The catch obtained at the end of the fishing season was >220 t, clearly above the average of the last five fishing seasons. As it was impossible to replicate the study, the results must be taken cautiously. At least one follow-up study is required to confirm the results and discard the possibility that the increase in production was due to natural environmental or biological variability.