A surgical instrument is a tool or implements specially designed to perform specific actions to achieve desired effects during surgery or operation, such as modifying biological tissue, or providing access to view it. With the passage of time, many different kinds of surgical instruments and tools have been invented. Some surgical instruments are designed for specific procedures or surgeries. Consequently, the nomenclature of surgical instruments follows specific patterns as a description of the action it performs (for example, scalpel, hemostat), the name of its inventor(s) (for example, the Kocher forceps), or a compound scientific name related to the class of surgery (for example, a tracheostomy is a tool used to perform a tracheostomy).

The expression surgical instruments are somewhat used interchangeably with surgical instruments, but its meaning in medical jargon is the activity of assisting a surgeon with the proper handling of surgical instruments during the operation, by a professional specialist, usually a surgical technologist or nurse practitioner

The responsibility of participating in the maintenance, knowledge of cleaning methods, preservation, conditioning, and packaging of surgical instruments for subsequent use is shared with the surgical instrumentation and the circulating nurse. The basic surgical instruments are classified according to their use: diaeresis, dissection, hemostasis, exposure, apprehension, exploration, and synthesis.