Objectives. To examine effects of unmet social needs on adherence to pediatric weight management intervention (PWMI).Methods. We examined individual associations of positive screens for parental stress, parental depression, food insecurity, and housing insecurity with intervention adherence, and associations of 0, 1 or 2, and 3 or 4 unmet social needs with adherence, among children enrolled in a 2017-2019 comparative effectiveness trial for 2 high-intensity PWMIs in Massachusetts. Models were adjusted for child age, body mass index (BMI), parent BMI, and intervention arm.Results. Families with versus without housing insecurity received a mean of 5.3 (SD = 8.0) versus 8.3 (SD = 10.9) contact hours (P < .01). There were no statistically significant differences in adherence for families reporting other unmet social needs. Children with 3 to 4 unmet social needs versus without received a mean of 5.2 (SD = 8.1) versus 9.2 (SD = 11.8) contact hours (P < .01). In fully adjusted models, those with housing insecurity attended a mean difference of -3.14 (95% confidence interval [CI] = -5.41, -0.88) hours versus those without. Those with 3 or 4 unmet social needs attended -3.74 (95% CI = -6.64, -0.84) hours less than those with none.Conclusions. Adherence to PWMIs was lower among children with housing insecurity and in families with 3 or 4 unmet social needs. Addressing social needs should be a priority of PWMIs to improve intervention adherence and reduce disparities in childhood obesity.Trial Registration: ClinicalTrials.gov identifier: NCT03012126.