This study draws on basic psychological needs (BPN) theory to investigate multiple ways that perceived relatedness is important for understanding students' help-seeking behavior in college science, technology, engineering, and mathematics (STEM) courses. Participants were 590 undergraduates (38% women; 65% European American, 24% Asian/Pacific Islander, 11% underrepresented minorities) who were enrolled in engineering coursework. We used structural equation modeling to examine the independent and interactive associations of students' BPN satisfaction (competence, relatedness, and autonomy) with their help-seeking behavior. Findings indicate that strong relatedness with both the instructor and peers are uniquely and differentially associated with specific types of adaptive help seeking (oriented to learning) and maladaptive help seeking (avoidance or asking for the answer), whereas competence and autonomy primarily explained differences in maladaptive types of help seeking. Moreover, many of these associations were dependent on students' relatedness with their instructor. Additional multigroup analyses revealed that instructor relatedness was especially critical for understanding women's help seeking. Results indicate that experiencing relatedness in college STEM programs--particularly positive relationships with instructors--is crucial for students' adaptive help seeking in difficult courses, while minimizing their maladaptive help-seeking behavior.