The objective was to test the hypothesis of no difference in facial swelling, pain, trismus and immediate quality of life after surgical removal of mandibular third molars, with or without post-operative cryotherapy. A MEDLINE (PubMed), EMBASE database and Cochrane library search in combination with a hand search of relevant journals were conducted by including human randomised controlled trials published in English until 17 July 2018. The search identified 37 titles. Six studies with low or unclear risk of bias fulfilled the inclusion criteria. Intermittent cryotherapy for 30 minutes during the first post-operative days significantly diminished facial swelling, pain and trismus compared with no cryotherapy. Patient's satisfaction and perception of recovery were significantly increased with cryotherapy. Therapeutic efficacy of intermittent cryotherapy on post-operative facial swelling, pain and trismus seems to be improved compared with continuous cryotherapy. Considerable variations in study design, diversity of used evaluation methods, outcome measures and various methodological confounding factors posed serious restrictions to review the literature in a quantitative systematic manner. Thus, conclusions drawn from the results of this systematic review should be interpreted with caution. Further well-designed randomised controlled trials including standardised protocol, larger patient sample, blinded outcome assessors, patient-reported outcome measures and three-dimensional volumetric analysis of facial swelling are required before evidence-based recommendations can be provided. K E Y W O R D S cryotherapy, dentistry, mandible, pain, review, third molar, trismus