The Croatian Medical Journal (CMJ) is a bimonthly scientific journal, that publishes mostly original articles. It is indexed in the Index Medicus/MEDLINE, Current Contents/Clinical Medicine, and the Science Citation Index Expanded. Since the CMJ's 15th anniversary in 2007, our aim has been to assess the importance of the Journal through its impact factor (IF) and immediacy index, with a particular focus placed on the proportion of self-citations. According the Web of Knowledge database, the current official IF for the CMJ is 0.825, ranking it 62nd out of 103 journals within the Thomson Scientific category "Medicine - General and Internal." The exclusion of self-citations resulted in a small decrease in the journal's rank - to 66th place. According to the Web of Science database, the predicted CMJ IF in 2007 is between 1.024 and 1.125, showing a clear increase. The immediacy index of the CMJ is continuously low, with a high contribution of self-citations, implying that articles published in the CMJ require more time to be cited, and that their topics are of particular interest to the journal's readers and contributors. Self-citations contributed significantly to the IF in the first few years after the journal was established. The proportion of independent citations progressively increased, and of all the citations included in the IF in 2007, almost 70% were fully independent. Some of these citations were from articles published in journals with IF higher than 5. Taken together, our data suggest that the CMJ has significantly improved its citation ratings during the last 15 years, confirming that a quality-oriented editorial policy in a small peripheral journal may result in a truly increased international visibility.