The growing number of publications presenting research findings, the pressure on scientists to produce publications in great quantity, and the shift in the business models of many journals increased importance of journals' editorial practices, which are well represented in guidelines for preparing the manuscript for submission. Journals have a special responsibility to protect research integrity and to keep trust in journal publishing. This study looked at information on editorial practices in the instructions for authors of Croatian Open Access journals. 283 instructions for authors from all disciplines were examined according to the broad range of publishing issues grouped in hierarchically organized categories. Mostly addressed issues were manuscript layout (276/283) and journal language (269/283). The most common ethical issues among journals from all disciplines were responsibility of author (73/283), funding (52/283), and accuracy (51/283). There are several ethical issues addressed significantly more often by biomedical journals, like responsibility of authors (14/30), publishing ethics (14/30), conflict of interest (12/30), funding (11/30), and authorship (11/30). In comparison with ethical issues common publishing issues like manuscript layout, manuscript elements, and type of paper were richly represented in journals from all disciplines.