This study aims to examine outcomes for temporomandibular joint (TMJ) arthroscopy in different Wilkes stages of internal derangement (ID) and factors relevant in relapse in those requiring further surgical management. A review was undertaken of patients who underwent TMJ arthroscopy from June 2017 until August 2019 at St George's Medical Centre, Christchurch, New Zealand. Those with a primary diagnosis of ID with adequate follow up were reviewed. Gender, pre-and post-operative visual analogue scale (VAS) pain scores and maximum incisal opening (MIO) according to Wilkes stages were statistically analysed. Parameters of those who underwent further surgery were assessed. Ninety-nine patients were reviewed with follow up time between 3 and 27 months. No difference in pre- and post-operative VAS pain scores occurred between Wilkes stages (p = 0.9527). Wilkes II patients had the lowest re-operation rates (6.7%). Twenty-one percent of patients underwent further surgery with either re-arthroscopy, arthrotomy or total joint replacement. Gender did not influence the risk of further surgery (p = 0.3451). Four Wilkes IV and 5 Wilkes V patients underwent TJR, with none from Wilkes II or III. This study shows TMJ arthroscopy should be considered a first line intervention in treating symptomatic ID regardless of initial Wilkes stage. A significant improvement in pain and functional levels occurred across all stages. No specific factors were identified for those undergoing further surgery. However, a trend towards open surgery and total joint replacement was seen in Wilkes IV and V patients.