This study examines the effect of diverse experiences on a firm’s alliance portfolio diversity (APD). Drawing on the organizational learning perspective, it argues that a firm’s learning from diverse experiences enables it to reap the benefits and mitigate the risks of high level of APD. Thus, an experienced firm may choose to form or maintain relationships with diverse partners to get the intended benefits of APD. In particular, the study hypothesizes that a focal firm’s product and international diversification experience, alliance experience, and alliance experience heterogeneity are positively associated with its APD. A longitudinal investigation of 90 Indian firms, for the period 2004–2014, provides support for all the hypothesized relationships. In general, findings, which are robust to multiple estimation methods, suggest that a firm’s diverse experiences influence its APD. Findings of this study contribute to the alliance portfolio and organizational learning literature by examining the experiential antecedents of APD.