OBJECTIVES: The role of real world evidence (RWE) and comparative effectiveness research (CER) has received increasing attention in recent years. Healthcare decision makers are often informed of these studies and findings through peer-reviewed publications. The purpose of this study was to examine the publication of studies that are not clinical randomized trials in major medical journals.  METHODS: Table of contents from 5 journals (New England Journal of Medicine (NEJM), Journal of American Medical Association (JAMA), Lancet, Circulation, and the British Medical Journal (BMJ)) were examined from January 2011 to December, 2015 to identify non-randomized controlled trials (non-RCTs).  To be classified as a study of interest, the research must have examined clinical and/or cost outcomes in which interventions are not randomly assigned and involved 2 or more interventions.  Non-RCTs were sub-classified into one of the following categories: retrospective cohort or case control; prospective cohort; meta-analysis (MA); network meta-analysis (NMA); modeled cost-effectiveness analysis (CEA); cost-effectiveness with randomized controlled trial (CEA-RCT); cost-consequence analysis (CCA); discrete event simulation (DES); and prediction model derivation/validation (PM). Descriptive, epidemiological evaluation, association, and trend studies were excluded.  RESULTS:  A total of 575 publications met inclusion criteria. Journals with the highest to lowest number of studies of interest were BMJ (N=269), JAMA (N=102), Circulation (N=100), Lancet (N=75), and NEJM (N=29). The most common study type was meta-analysis (N=322). Only eight CEA-RCT studies were published during the study time frame. A total of 72 retrospective and 36 prospective cohort studies were published, with 12 of the prospective studies being published in NEJM. For all 5 journals, publication of non-RCTs peaked in 2012.  CONCLUSIONS: Publication of non-RCT studies is not common, especially in NEJM. Among the five studied journals, the BMJ published the highest number of non-RCT studies and the vast majority were meta-analyses.