Supervision is used in counselling, psychotherapy, and other mental health disciplines as well as many other professions engaged in working with people. Supervision may be applied as well to practitioners in somatic disciplines for their preparatory work for patients as well as collateral with patients. Supervision is a replacement instead of formal retrospective inspection, delivering evidence about the skills of the supervised practitioners.

It consists of the practitioner meeting regularly with another professional, not necessarily more senior, but normally with training in the skills of supervision, to discuss casework and other professional issues in a structured way. This is often known as clinical or counselling supervision (consultation differs in being optional advice from someone without a supervisor's formal authority). The purpose is to assist the practitioner to learn from his or her experience and progress in expertise, as well as to ensure good service to the client or patient. Learning shall be applied to planning work as well as to diagnostic work and therapeutic work.

Milne (2007) defined clinical supervision as: "The formal provision, by approved supervisors, of a relationship-based education and training that is work-focused and which manages, supports, develops and evaluates the work of colleague/s". The main methods that supervisors use are corrective feedback on the supervisee's performance, teaching, and collaborative goal-setting. It therefore differs from related activities, such as mentoring and coaching, by incorporating an evaluative component. Supervision's objectives are "normative" (e.g. quality control), "restorative" (e.g. encourage emotional processing) and "formative" (e.g. maintaining and facilitating supervisees' competence, capability and general effectiveness).

Some practitioners (e.g. art, music and drama therapists, chaplains, psychologists, and mental health occupational therapists) have used this practice for many years. In other disciplines the practice may be a new concept. For NHS nurses, the use of clinical supervision is expected as part of good practice. In a randomly controlled trial in Australia, White and Winstanley looked at the relationships between supervision, quality of nursing care and patient outcomes, and found that supervision had sustainable beneficial effects for supervisors and supervisees. Waskett believes that maintaining the practice of clinical supervision always requires managerial and systemic backing, and has examined the practicalities of introducing and embedding clinical supervision into large organisations such as NHS Trusts (2009, 2010). Clinical supervision has some overlap with managerial activities, mentorship, and preceptorship, though all of these end or become less direct as staff develop into senior and autonomous roles.

Key issues around clinical supervision in healthcare raised have included time and financial investment. It has however been suggested that quality improvement gained, reduced sick leave and burnout, and improved recruitment and retention make the process worthwhile.