There are intense efforts from pharmaceutical manufacturers to discover novel approaches to finding new drug candidates for cancer treatment. Sea cucumber is widely consumed in traditional medicine. Its anticancer potential is associated with the content of a bioactive compound known as saponin. The goal of this paper was to compare the hemolytic activity and cytotoxicity of six sea cucumber extracts. The hemolytic assay confirmed the presence of saponins. Two methods examined the cytotoxicity of extracts: (i) lethality assay in brine shrimp (Artemia salina) (BSA) and (ii) tetrazolium dye-based colorimetric (MTT) assay in human cancer cell lines, such as colorectal carcinoma (HCT-116), epitheliod carcinoma (Hela), epidermoid carcinoma (HEP2) and human prostate cancer  (PC3). Hemolytic activity was observed in H. atra, H. edulis, B. marmorata and A. mauritiana, while H. polii and H. leucospilota showed no hemolytic activity. The data in the BSA bioassay showed high and moderate cytotoxic activity. The more effective extracts were H. atra and B. marmorata. The average IC₅₀ of H. atra extract against Hela, HeP2, HCT-116andPC3 cells were 9.14±0.8, 10.39±0.9, 11.43±1, 17.90±1.5μg/ ml, respectively. The data confirmed that the Egyptian sea cucumber species may serve as an exciting source for discovering novel anticancer drugs.