PurposeThe purpose of this paper is to examine how participatory decision‐making processes in top management teams (TMT) influence strategic decision effectiveness and firm performance.Design/methodology/approachData from 94 TMTs are collected from structured surveys. Each firm's CEO provides data on strategic decision effectiveness, and a senior executive member of the TMT provided data on participatory decision‐making processes and firm performance.FindingsResults show that participatory decision‐making processes in the TMT are positively associated with decision effectiveness, but there is both a direct and an indirect relationship (through decision effectiveness) between participatory decision‐making processes and firm performance.Originality/valueThis paper sheds light on the importance of joint decision‐making processes among TMT members for improving choices and enhances firm performance.