In scientific publishing, a paper is a scientific article that is published in a scientific journal. It contains novel research results or reviews existing results. Such a paper, also often called an article, will typically undergo a process of peer review by one or more referees in order to check that the content of the paper is suitable for publication in the journal. A paper may undergo a series of reviews, edits and re-submissions before finally being accepted or rejected for publication. This process may take some years, particularly for the most popular journals where the number of acceptable articles outnumbers the space for printing. Due to this, many scientists offer a 'pre-print' copy of their paper for free download from their personal or institutional website.

Many journals, particularly newer ones, are now published in electronic form only. Paper journals are often made available online to members of academic institutions. Sometimes these electronic versions are available immediately upon publication of the paper version, but more frequently the publisher will insist on a delay of two to five years before making electronic download available in order to protect revenue streams.

See also: List of scientific journals, citation index, online papers search engines, Category:EPrint Archives.