In open innovation processes, when partners actively transfer technology and knowledge across firm boundaries, effective and timely problem solving is the key to progress any given collaborative project. We propose that the problems a development team need to solve may be conceptualized as ambiguous, equivocal, uncertain or complex, or a combination of the four. By means of a multiple case study of new product and technology development at global manufacturing firms, we propose that efficient solution search is contingent on matching the nature of a problem with the appropriate solution search strategy. We identify four solution search strategies, so far tentatively referred to as: analytic search, interpretative search, restrictive search, and acquisition search. The article elaborates the key activities, effects and trade-offs of these strategies and provides managerial implications for improved problem solving in open and collaborative development.