This study is focused on developing and validating the discovery-based modules in chemistry. This exploration was initiated in response to the criminology student's least-learned concepts in the general (organic) chemistry course. A descriptive–developmental approach was utilized and guided by the Analysis-Design-Development-Implementation-Evaluation (ADDIE) model in the development and validation of the discovery-based modules. In the study, two discovery-based modules were developed. Each module had the following parts: a pre-test, an overview, safety precautions, preparation, a review, the activity itself, a discussion after the activity, a post-activity test, an application, and a reference. Five (5) chemistry teacher experts and five (5) criminology student-users evaluated the aspects of the discovery-based modules using the validation and evaluation forms of the study. The researcher interviewed the criminology student-users using the validated interview guide questions to determine their feedback using the modules. Findings revealed that both chemistry teacher experts and criminology student-users rated the two developed discovery-based modules as excellent and strongly agreed on all pertaining aspects of the modules, in terms of objectives, content, format and language, presentation, and usefulness. The feedback of the student-users revealed interactive, well-designed, discovery-based, and outcome-based themes perceived as the characteristics of the developed chemistry modules. Therefore, it was concluded that the developed discovery-based modules in chemistry are valid, acceptable, and could be used as supplementary material for criminology students and further recommended for possible replication to cover the other least-learned chemistry concepts.