Background & aims. Author instructions in medical jounals inform on key elements of the manuscript preparation and submission, authorship and author responsibilities, copyright, permissions for use etc. In most cases, the publishers are following the international recommendations, like those of ICMJE. The aim of this study was to find to what extent the Croatian medical journals follow these recommendations. Methods. The sample included 38 journals listed in the biomedical and health care category at the national open access platform Hrčak. The analysis was done in June 2016. Results. The results showed that 60% of the analysed journals mentioned ICMJE recommendations in their author instructions. The signed statement of authorship is required by 47% of journals while half of them mentioned the ICMJE authorship criteria explicitly. Authors are asked to confirm that the submitted manuscript has not already been published or submitted to another journal by 68% of journals. A statement on disclosure of conflicts of interests was found in 45% of guidelines. Transfer of copyright is required by 45% of journals. Conclusion. Strict adherence to the international recommendations regarding authorship, peer review and manuscript selection could increase the quality of journals.