Network- and cohesion-based social capital may play an important role in improving mental health. However, there is limited understanding about these relationships among adults in Taiwan. The aim of this study was to examine the association between individual-level network and cohesion-based social capital and depressive symptoms among a population-based sample of Taiwanese adults. Data were obtained from the 1997 Taiwan Social Change Survey (n = 2,598). The 20-item Center for Epidemiological Studies Depression Scale was used to measure depressive symptom scores; ⩾16 represented high depressive symptoms. Network-based social capital was measured using a position generator. Two dimensions of cohesion-based social capital were assessed: cognitive (perceived neighborhood trust and reciprocity) and structural (local community participation and organizational participation). Multivariable log-binomial regression models, weighted to account for the complex sampling design and adjusted for confounders, estimated prevalence ratios and 95% confidence intervals (CIs) to examine the association between each social capital measure and depressive symptoms. In this study, 29.6% of respondents were classified as having high depressive symptom scores. Higher scores of composite cognitive social capital (adjusted Prevalence Ratios (aPR) = 0.92, 95% CI = [0.90, 0.95]) and structural social capital (aPR = 0.80, 95% CI = [0.65, 0.99]) were associated with a lower likelihood of high depressive symptom scores after controlling for confounders. However, there was no association between network social capital and depressive symptoms. The findings suggest that the relationship between social capital and depressive symptoms in Taiwan differs according to the specific dimension of social capital assessed. Differentiating between network- and cohesion-based social capital merits greater attention to inform our understanding of building social capital to promote and improve mental health outcomes.