This document summarizes a study on the culture of assessment in Croatian academic and public libraries. It describes the study's project goals, hypotheses, methodology, instruments, survey sample, and key results. The study found that while organizational culture in Croatian libraries is becoming more open to assessment, it has yet to fully adopt assessment practices. Public libraries appeared more open to assessment than academic libraries, though academic libraries had done more assessment work already. In conclusion, the culture of assessment is still developing in Croatian libraries but progress is being made.