Objective To date, most investigations of mental health in pregnant women have focused on depression or substance use. This study aimed to (a) delineate the relationships between symptoms of attention-deficit/hyperactivity disorder (ADHD) and prenatal health behaviors and (b) explore whether the symptom clusters of ADHD differentially predict prenatal health behaviors (e.g., physical strain, healthy eating, prenatal vitamin use). Method A total of 198 pregnant women (mean age = 27.94 years) completed measures of ADHD symptoms, prenatal health behaviors, and depression. Results Inattention, hyperactivity, and impulsivity/emotional lability all evidenced significant relationships with the prenatal health behaviors, each differentially predicting different prenatal health behaviors. Conclusion As decreased engagement in adequate prenatal health behaviors puts both the mother and fetus at risk for negative birth outcomes, future research should work to develop a brief ADHD screen to be used in obstetric clinics and should investigate these relationships within a sample of women with a diagnosis of ADHD.