Medical writing is the activity of producing scientific documentation by a specialized writer. The medical writer typically is not one of the scientists or doctors who performed the research.

A medical writer, working with doctors, scientists, and other subject matter experts, creates documents that effectively and clearly describe research results, product use, and other medical information. The medical writer also makes sure the documents comply with regulatory, journal, or other guidelines in terms of content, format and structure.

Medical writing as a function became established in the pharmaceutical world because the industry recognized it requires special skill to produce well-structured documents that present information clearly and concisely. A growing number of new drugs go through the increasingly complex process of clinical trials and regulatory procedures that lead to market approval. This drives a demand for well written, standards-compliant documents that science professionals can read and understand easily and quickly.