Despite evidence for heritable variation in cannabis involvement and the discovery of cannabinoid receptors and their endogenous ligands, no consistent patterns have emerged from candidate endocannabinoid (eCB) genetic association studies of cannabis involvement. Given interactions between eCB and stress systems and associations between childhood stress and cannabis involvement, it may be important to consider childhood adversity in the context of eCB-related genetic variation. We employed a system-level gene-based analysis of data from the Comorbidity and Trauma Study (N = 1,558) to examine whether genetic variation in 6 eCB genes (anabolism: DAGLA, DAGLB, NAPEPLD, catabolism: MGLL, FAAH, binding: CNR1; SNPs N = 65) and childhood sexual abuse (CSA) predicts cannabis dependence symptoms. Significant interactions with CSA emerged for MGLL at the gene-level (p = .009), and for rs604300 within MGLL (ΔR2 = .007, p