Objective: High rates of depression and posttraumatic stress disorder (PTSD) contribute to sexual risk, particularly in men who have sex with men (MSM) who have experienced childhood sexual abuse. The comorbidity between depression and PTSD and mechanisms by which they contribute to sexual risk in MSM remain unclear. This study sought to demonstrate the feasibility and utility of a network approach to (a) characterize symptom interconnections between depression and PTSD in MSM, (b) identify specific symptoms related to sexual risk behavior, and (c) compare symptom networks across groups at different levels of risk. Method: Cross-sectional baseline data were collected from 296 HIV-negative urban MSM as part of a multisite randomized intervention trial. Symptoms of depression and PTSD were self-reported along with sexual risk behavior. Analyses were performed in R using regularized partial correlation network modeling. Results: Network analyses revealed complex associations between depression and PTSD symptoms and in relation to sexual risk behavior. While symptoms clustered within their respective disorders, depression and PTSD were connected at key symptom nodes (e.g., sleep, concentration). Specific symptoms (e.g., avoiding thoughts and feelings) were linked to sexual risk behavior. Network comparisons across risk groups suggested avoidant processes could be more readily activated in higher-risk individuals, whereas hyperarousal symptoms may be more salient and protective for lower-risk individuals. Conclusions: This study is one of the earliest network analyses of depression and PTSD, and first to extend this inquiry to health behavior. Symptom-level investigations may clarify mechanisms underlying psychological comorbidity and behavioral risk in MSM and refine targets for intervention/prevention.