Empirical support for the process and mechanism of interactions with knowledge-intensive business services (KIBS) is scarce, particularly with regard to small and medium manufacturing enterprises (SMMEs). Our study investigated how four SMMEs in China’s electrical appliance industry cluster attained high performance through interactions with KIBS. For our research, knowledge integration can be understood as knowledge identification, knowledge accession, and knowledge utilization. We investigated the mechanism involved in interactions between SMMEs and KIBS by tentative multiple case studies, and found that interactions with technology-based KIBS improved the performance of SMMEs by influencing their knowledge accession and knowledge utilization. Interactions with traditional professional KIBS, however, mainly influence SMMEs’ knowledge identification and knowledge accession. technology-based KIBS generally acts as a knowledge source and professional KIBS as a knowledge bridge for SMMEs. Interaction with technology-based KIBS is a kind of complementary interaction, while interaction with professional KIBS is a kind of supplementary interaction.