This paper shows key steps in the development of a Model for Digitally Mature Schools in Croatia and reveals the results of assessment of digital maturity of schools in Croatia. In total, 151 primary and secondary schools were assessed against maturity levels using the instrument, and two different methods for gathering the data: self-evaluation and external evaluation. Notable differences were recorded between results of self-evaluation and external evaluation in favour of self-evaluation. Some of the factors that contributed to differences are lack of experience in conducting self-evaluation and additional training for external evaluators in opposition to written guidelines for conducting self-evaluation. The next step is to refine and upgrade the instrument based on comments and suggestions gathered during external evaluation and self-evaluation. Towards the end of the pilot project the final self-evaluation and external evaluation is planned to monitor schools’ progress. In order to lower the differences between results of self-evaluation and external evaluation, besides upgraded instrument, school staff will be more intensively prepared for conducting self-evaluation.