Background Herbal medicine has gathered increasing attention in contemporary healthcare practices, offering natural remedies for a wide range of ailments such asskin diseases, liver disorders,bronchitis, and asthma. Among the plethora of medicinal plants, Croton bonplandianum, commonly known as "Ban Tulsi," holds significant medicinal value owing to its diverse pharmacological properties. This study investigated the cytotoxicity, embryotoxicity, antidiabetic, and anticariogenic effects of an ethanolic extract derived from C. bonplandianum.The research objectives were to explore the preparation of an ethanolic extract of C. bonplandianum and employ a multifaceted approach by evaluating its cytotoxicity, embryotoxicity, anticariogenic, and antidiabetic potentials. Materials and methods In this study, the β-glucosidase inhibitory and the α-amylase inhibitory assays were utilized to evaluate the antidiabetic activity of theC. bonplandianum ethanolic extract. The in vitro cytotoxicity activity was assessed by using the brine shrimp lethality assay (BSLA), and embryotoxicity was evaluated using zebrafish embryos and larvae. Through the agar well diffusion method and the time-kill curve analysis, the anticariogenic activity was evaluated. Results In α-amylase andβ-glucosidase inhibitory assays, the ethanolic extract ofC. bonplandianum showed potent antidiabetic properties, near those ofstandard acarbose. The cytotoxicity evaluation using the BSLA showed less toxicity. The anticariogenic activity of the ethanolic extract of C. bonplandianumwas assessed by comparing the standard (Amoxyrite) in terms of its zone of inhibition against oral pathogens such asStreptococcus mutans and Lactobacillus species (spp.). The antibacterial efficiency was validated using a time-kill curve assay in which the study depends on the concentration of the bacterial pathogenic organisms, namely, Lactobacillus spp. and S. mutans. In embryotoxicity evaluation, there were no morphological malformations in zebrafish larvae or embryos when exposed to high concentrations of C. bonplandianum ethanolic extract. Conclusion The ethanolic extract ofC. bonplandianum exhibited promising antidiabetic and anticariogenic effects, supporting its conventional usage inalternative medicine. The outcomes of these research analyses suggest the plantpotential as a natural source of compounds with bioactive qualities and can be utilized in the healthcare and pharmaceutical industries.