This paper draws on survey data to clarify whether small high-technology firms benefit most from adopting greater numbers of new product development (NPD) tools to support NPD projects, or from using tools more thoroughly. This is an important issue given that small firms adopt NPD tools despite facing acute resource limitations and using informal processes. Prior studies of the performance impact of NPD tools have focused on large firms, and very few have assessed the performance impact of using NPD tools to higher levels of thoroughness. The paper covers tools across functional/technical and management/marketing aspects of NPD, and measures performance in process, product and market. We found that increasing the number of tools adopted did not measurably improve performance, in contrast to prior findings in larger firms. Instead, we found that firms obtained meaningfully improved NPD performance from using tools at higher average levels of thoroughness. Higher average thoroughness produced statistically significant performance benefits across seven of our nine performance measures. Our findings imply that small firms should emphasize selective but thorough and well-designed implementation of NPD tools.