This study analyzed the bioactive compound content and nutritional composition of Hassawi Popper (Cucurbita moschata), a local landrace of pumpkin cultivated in Saudi Arabia, and compared it with other pumpkin cultivars from different regions imported to Saudi Arabia. The chemical composition, pH, color parameters, amino acid profile, mineral composition, carotenoid profile, vitamin content, phenolic acid and flavonoid content, and antioxidant activity of Hassawi Popper and two other pumpkin varieties (Cucurbita maxima and Cucurbita pepo) were determined using various analytical methods. The results showed that Hassawi Popper had higher levels of protein, ash, total dietary fiber, calcium, magnesium, phosphorus, manganese, iron, zinc, copper, lysine, isoleucine, phenylalanine, aspartic acid, serine, glutamic acid, alanine, proline, β-carotene, α-carotene, vitamin B1, vitamin B2, vitamin B5, vitamin B6, total phenolic content, total flavonoid content, condensed tannin content, and antioxidant activity than the other two varieties. These findings suggest that Hassawi Popper is a valuable source of bioactive compounds and nutrients that can provide health benefits for consumers. The study also provides valuable insights for further research on the genetic diversity and phytochemical properties of Cucurbita moschata cultivars from different regions.