Objectives: This study aims at exploring the knowledge of women of reproductive age who underwent bariatric surgery in Jordan regarding its effect on birth outcomes. Methods: A cross-sectional study was conducted on 183 women (aged 15–49) who had undergone bariatric surgery at the Jordan University Hospital in Amman, Jordan, between 2016 and 2019, using telephone interviews with conveniently selected participants’ samples. The survey tool obtained data on women’s knowledge and other sociodemographic, obstetric health, and bariatric surgery information. Unfavorable birth outcomes include preterm delivery, small for gestational age, congenital abnormalities, low birth weight, and admission to the neonatal critical care unit. Results: More than half of the participants did not know about the possible unfavorable birth outcomes after bariatric surgery and related practice guidelines. This is shown in their median score of 3 (interquartile range: 2–4) out of a maximum possible score of 8. Women who had a good score (>4) had received counseling about unfavorable bariatric surgery outcomes from their surgeon ( p < 0.013); those who had educational qualifications higher than secondary school ( p < 0.001) as well as those who were employed ( p < 0.008) and believed that the surgery would affect the newborn ( p < 0.001). The median score was also unfavorably associated with the parity of the participants ( p < 0.003). Conclusion: The extent of knowledge regarding the unfavorable birth outcome of bariatric surgery is low among women who underwent bariatric surgery at Jordan University Hospital in Jordan. Improving health literacy and information on bariatric surgery implications on pregnancy and birth outcomes amongst women of reproductive age is a recommendation from this study.