Citations and impact factor play a major role in how journals are perceived by authors and by external agencies such as granting bodies and universities. The impact factor was devised by Eugene Garfield, the founder of the Institute for Scientific Information, now part of Thomson Scientific, a large, worldwide, US-based publisher. Impact factors are calculated each year by the Institute for Scientific Information for the journals it indexes, and the factors and indexes are published in Journal Citation Reports.1–2 The validity of the impact factor is controversial because many extraneous factors that are not necessarily directly linked to the quality of the publications of a journal can influence the rating achieved. Nevertheless, it remains the default method for assessing the publishing success of a journal. The impact factor is calculated by dividing the number of citations to publications in the previous 2 years by the number of articles published. The impact factor reflects the citation rate of the average article in a journal and not a specific article. Published critical appraisal of the impact factor is limited.2–9 There appears to be a weak relationship between the impact factor of a journal and the subsequent citation rate of a given article.3In recent times, many new journals have had an increase in their impact factor, while many journals with long standing reputations have not, and in some cases their impact factor has fallen.4Journals with an increasing impact factor cite active recruitment of better articles from researchers, offering better author services, boosting the journals media profile, and more careful article selection. Editors frequently report mixed feelings about using the impact factor to evaluate journals.5There is limited information on how scientific information is distributed among journals. Only a few journals out of many have contributed significantly to a specific topic or area, and not surprisingly these are mainly journals that are topic based rather than being general. Recent citation analyses in the sciences have revealed that 150 journals account for 25% of publications and 50% of citations, while 2,000 journals account for 85% of publications and 95% of citations6 However the core group of significant journals is not static, and its composition is changing constantly. There is a proliferation of new journals and the Institute for Scientific Information reviews 2,000 new journal titles annually but selects only 10 to 12% for longer-term impact factor evaluation.6Other methods of assessing journals and their publications exist, such as overall citation rate, citation half-life, and immediacy factor, but these have not gained much traction as yet. Within any one journal, the percentage of articles being cited can vary. One study7 has reported that approximately 17% of articles accrued 50% of the total citations for the journals studied. These authors7 have also argued strongly for quoting the noncitation rate of a journal because it is independent of the total number of citations. Despite diversity of opinion on the merits of the impact factor, it remains an important variable in choosing the journal in which to publish. Furthermore, it is sensible to try to assess which journals are on the ascent with respect to impact factor and which are not.