Seven points to include in your cover letter

A professionally written cover letter gives a strong first impression and indicates to the journal editor that the work is of a high quality. Above all, your cover letter should persuade the journal editor that your manuscript is appropriate for his or her journal. 

Include the following seven points, keeping them concise:

1. A personalized introduction. Find out the name of the journal’s editor-in-chief or equivalent instead of using the generic “Dear Sir/Madam”. 
2. The manuscript title and type of publication (e.g. Original Article, Case Report, Brief Communication). 
3. The background to your research, what is known in the field, and what your reasons were for conducting the study. This should be explained concisely in two to three sentences, and will help the journal editors, reviewers, and potential readers understand your motivation for carrying out the study. 
4. The main findings of your study and how they were obtained. In the next paragraph, the study methods and results should be briefly described. Do not include too many data or statistical details here, but provide a concise overview of the most important findings. 
5. The importance and novelty of your work and the implications of your results for the field. Continuing in the same paragraph, the importance of your work should be highlighted. Try to explain the implications that your results have in the real world. To emphasize the novelty of your findings you could write “To our knowledge, this is the first report showing that…”
6. Why your findings would be of interest to the journal’s target readership. Here, you need to tailor your reason (and possible revise your article’s Introduction and Discussion) to match the target journal’s aims and scope statement. If your manuscript has been rejected by your first-choice journal, this tailored reason should not be reused when you are submitting the manuscript to another journal. Instead, it should be rewritten to closely match the aims and scope of the new target journal.
7. Why your findings are important. You may also mention topical reasons here, such as recent media attention, government policy consultation, debate in the field, or a recent related article or editorial was  published in the target journal.

Other important information to include

Some journals have specific requirements for what should be included in a cover letter, and these will be listed in the author guidelines. 

Editors usually wish to know that your manuscript has not been submitted elsewhere, that it is not under consideration by another journal, and that all authors have approved the manuscript and its submission to the journal. Some journals also want to know relevant conflict of interest information and any roles played by the funding agency in the study. 

Other journals might require you to declare any previous correspondence about the manuscript, previous rejections at other journals, related manuscripts being considered at other journals, or previous related publications. 

Finishing touches

End your cover letter with the following information:

• Recommendations of peer reviewers. If your cover letter succeeds in persuading the journal editor to send your manuscript on for peer review, you can help speed up the next step by suggesting the names of potential reviewers. These people should not be friends, family, collaborators, or co-authors within the past 5 years. Instead, suggest researchers who are knowledgeable in the field, possibly from several different countries. If possible, ry to suggest less senior scientists who will have more time to carry out peer review than department heads; But in some specialist fields, you may have to nominate a senior professor if experts are scarce. You could include a sentence such as “We would like to suggest the following as potential peer reviewers of our study”, and then provide the full and correct contact details for three to five scientists, including their e-mail addresses. You must not contact the reviewers directly. 
• Exclusion of peer reviewers. You may also list reviewers who you would like to be excluded from peer review, perhaps because of conflicts of interest (but make sure that you give a valid reason). 
• Concluding remarks. Politely thank the editor for his or her time: “Thank you for receiving our manuscript and considering it for review. We appreciate your time and look forward to hearing from you at your earliest convenience. Please address all correspondence to…” Then, the corresponding author should provide their full contact details and sign off using “Yours sincerely”.

Choose reviewers who have published in your target journal; they will be known to the journal editor. Those reviewers already have a relationship with the journal, so they will be more likely to accept.