After two decades of meagre results in post-Soviet regionalism, the Eurasian Economic Union (EAEU) is the first gleam of hope. However, research on the EAEU is mostly Russia-centred and focused on trade issues, which leaves the small states' perspectives and developmental aspects, such as the EAEU's industrial cooperation agenda, understudied. The small states might disproportionately benefit from a shift towards developmental regionalism, but there are also many challenges associated with this issue. Thus, this paper examines Armenia's and Belarus' industrial development prospects in the framework of the EAEU. Based on Regulation Theory, the paper triangulates data from national, supranational and international organisations, official EAEU documents and reports with insights from 10 expert interviews with policy makers, policy advisers and management consultants. The paper identifies diverging (and sometimes conflicting) interests regarding the relevance and concrete arrangement of industrial cooperation, which has particular implications for smaller member states like Armenia and Belarus.