A technical report (also scientific report) is a document that describes the process, progress or results of a scientific or technical investigation or the status of a scientific or technical research problem.[1]​ It may also include recommendations and conclusions from the research. Unlike other scientific publications, such as scientific journals and the proceedings of some academic conferences, technical reports rarely undergo extensive independent peer review before publication. They can be considered gray literature. When there is a review process, it is often limited to within the parent organization. Similarly, there are no formal publication procedures for such reports, except where established locally.

Technical reports are today an important source of scientific and technical information. They are prepared for internal or broader distribution by many organizations, most of which lack the extensive editing and printing facilities of commercial publishers.

Technical reports are often prepared for sponsors of research projects. Another case in which a technical report may be produced is when more information is produced for an academic article than is acceptable or feasible to publish in a peer-reviewed journal; Examples of this include in-depth experimental details, additional results, or the architecture of a computer model. Researchers can also publish work early as a technical report to establish novelty, without having to wait for the long production schedules of academic journals. Technical reports are considered "non-archival" publications and may therefore be freely published elsewhere in peer-reviewed venues with or without modifications.

Technical reports are now commonly published in electronic format, either on the Internet or on the intranet of the originating organization.

Many organizations compile their technical reports into a formal series. Reports are assigned an identifier (report number, volume number) and share a common cover layout. The entire series may be uniquely identified by an ISSN.

A registration scheme for a globally unique International Standard Technical Report Number (ISRN) was standardized in 1994 (ISO 10444), but was never implemented in practice. ISO eventually retired this standard in December 2007.[4] It was intended to be an international extension of a reporting identification scheme used by US government agencies (ANSI/NISO Z39.23).