The aim of this study is to inspect differences in internationalisation level of firms from a transitional economy based on their innovation outcomes, open innovation and organisational learning practices. Results indicate that firms with lower internationalisation level owe their innovation success to coupled and outbound open innovation practices that originate from market research, competitor tracking and public information. Mediating effect of outbound innovation is present in the relationship between market research and innovation success. Firms with higher internationalisation level do not exhibit significant effect of open innovation on innovation success, but their organisational learning antecedents such as market research and research and development negatively affect innovation success, while public information and forecasting have a significant positive effect on innovation success. The major contribution of this study is the understanding of how organisational learning antecedents and open innovation practices interact in firms with different internationalisation levels, whereby firms with higher internationalisation level already have competitive advantage that lower internationalisation firms need to achieve.