Background: Many manuscripts submitted to biomedical journals are rejected for reasons that include low‑quality of the manuscripts.Aim: The aim of this study is to identify and characterize the common errors in manuscripts submitted to medical journals based in Africa and Asia. Materials and Methods: Reviewers’ reports on 42 manuscripts were analyzed qualitatively using deductive coding, and quantitatively to determine the errors by sections of the manuscripts. The study included only reviews on full length original research articles. Results: Results showed that 66.7% (28/42) of the manuscripts had flaws in the introduction, 85.7% (36/42) in materials and methods, 66.7% (28/42) in the results, 71.4% (30/42) in discussion, 69.0% (29/42) in references, and 81.1% (34/42) in the general sections. Qualitative analysis of the reviews revealed 22 themes. Most common flaws identified were improper review of literature, provision of insufficient detailed methodology, unsystematic or illogical presentation of results, and unsupported conclusions. Others were inconsistent or nonconforming citations, and lack of good grammatical writing.Conclusions: The results show that many of the manuscripts had remarkable errors and demonstrate the need for attention to detail in study design and manuscript preparation and for further training of medical scientists in the techniques of manuscript writing for journal publication.Key words: Academic writing, Africa, Asia, Manuscript preparation, Peer review