Collaboration skill has become one of the key skills in the 21st century both in education and work life. That is why educators need to learn about their students' preferences and readiness in collaboration in the classroom. This study aims to develop a scale that lets secondary school students self-evaluate their collaboration skills. To follow this aim, a general survey methodology was used. A draft scale consisting of 33 items was developed through the relevant literature and was examined by experts. Then, the draft version was applied to a total of 402 secondary school students at a state secondary school in Aksaray city in Turkey in the 2019-2020 academic year. The data was subjected to first explanatory then confirmatory factor analysis. The explanatory factor analysis and first and second stage confirmatory factor analysis results indicate that the Scale for Self-Evaluation of Collaboration Skills (SSCS) with 29 items under three sub-dimensions--namely affective considerations, collaboration process, and roles and responsibilities- is a valid and reliable tool to examine collaboration skills of secondary school students.