The majority of academic papers are scarcely cited while a few others are highly cited. A large number of studies indicate that there are many factors influencing the number of citations. An actual review is missing that provides a comprehensive review of the factors predicting the frequency of citations. In this review, we performed a search in WoS, Scopus, PubMed and Medline to retrieve relevant papers. In overall, 2087 papers were retrieved among which 198 relevant papers were included in the study. Three general categories with twenty eight factors were identified to be related to the number of citations:​ Category one:​ ‘‘paper related factors’’:​ quality of paper;​ novelty and interest of subject;​ characteristics of fields and study topics;​ methodology;​ document type;​ study design;​ characteristics of results and discussion;​ use of figures and appendix in papers;​ characteristics of the titles and abstracts;​ characteristics of references;​ length of paper;​ age of paper;​ early citation and speed of citation;​ accessibility and visibility of papers. Category two:​ ‘‘journal related factors’’:​ journal impact factor;​ language of journal;​ scope of journal;​ form of publication. Category three:​ ‘‘author(s) related factors’’:​ number of authors;​ author’s reputation;​ author’s academic rank;​ self-citations;​ international and national collaboration of authors;​ authors’ country;​ gender, age and race of authors;​ author’s productivity;​ organizational features;​ and funding. Probably some factors such as the quality of the paper, journal impact factor, number of authors, visibility and international cooperation are stronger predictors for citations, than authors’ gender, age and race;​ characteristics of results and discussion and so on.