Medical writing involves creating well-structured scientific documents that include clinical research documents, content for healthcare websites, health magazines, journals and news. Medical writing can be classified into two types: Regulatory medical writing and Educational medical writing.

A medical writer is a person who applies the principles of clinical research in developing clinical trial documents that effectively and clearly describe research results, product use, and other medical information. The Medical writers develops any of the five modules of the Common Technical Document. The medical writers also ensure that their 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 and contract research organization industry because the industry recognized that it requires special skill to produce well-structured documents that present information clearly and concisely. All new drugs go through the increasingly complex process of clinical trials and regulatory procedures that lead to market approval. This demand for the clear articulation of medical science, drives the demand for well written, standards-compliant documents that medical professionals can easily and quickly read and understand. Similarly, medical institutions engage in translational research, and some medical writers have experience offering writing support to the principal investigators for grant applications and specialized publications.