Purpose - The purpose of this paper is to explore the relevant factors that influence the implementation of innovation contests, an open innovation (OI) practice that has been extensively reported in the literature as a managerial tool for external knowledge search. The authors focus the study on the context of small and medium enterprises (SMEs). Design/methodology/approach - The approach is a retrospective case study. This methodology allows an in-depth view into a Spanish SME that successfully undertook two new product development processes thanks to the deployment of innovation contests. Findings - The main context factors influencing innovation contests as managerial tool are ambidexterity, technological and marketing turbulence and intermediaries, among others. Regarding design factors, this work highlights the role of attraction and facilitation. Additionally, the repetitive implementation of innovation contests creates a corporate culture that promotes OI activities. Practical implications - Managers will understand that they can use innovation contests as a managerial tool, and knowing the factors that need to be taken into account when implementing an innovation contest will help SMEs managers to make better use of this practice. Originality/value - This case study enriches the literature of both innovation contests and topics relevant to SMEs. Based on a theoretical framework of the design factors that influence the implementation of innovation contests, the authors propose a research framework that incorporates those context factors in association with an SME.