Introduction Internal temporomandibular joint (TMJ) disorders are present in approximately 80% of patients with symptomatic temporomandibular disorders. Among the minimally invasive therapies, we find the intra-articular infiltration of substances, such as corticosteroids, hyaluronic acid or platelet-rich plasma accompanied or not by an arthrocentesis. There are several studies on minimally invasive therapy for internal TMJ disorders; however, none compares the effectiveness of the different intra-articular corticosteroids to each other. The purpose of this study is to evaluate the effectiveness of the different intra-articular corticosteroids for the treatment of internal disorders of the TMJ and compare them to each other or to other minimally invasive therapies. Methods and analysis A systematic search will be carried out up to December 2019 in the electronic databases: Medline, Cochrane Library, EMBASE, SCOPUS and LILACS. Randomised clinical trials evaluating patients with internal disorders of the TMJ, with intra-articular corticosteroid therapy and comparing these to each other and/or to other minimally invasive therapy will be included. The main outcomes will be pain and range of motion measured through validated scales. Two review authors will independently screen search results, extract data from included studies and assess the risk of bias in those studies using the Revised Cochrane Risk of Bias Tool (RoB 2.0). In the case of any discrepancy and failure to reach consensus, this will be resolved by a third reviewer. A network meta-analysis will be conducted based on direct comparisons to generate indirect comparisons of the different treatments. Data will be combined in a meta-analysis using a random effects model. The principles of the Grading of Recommendations Assessment, Development and Evaluation (GRADE) system will be used to assess the overall quality of the body of evidence associated with the main results. Ethics and dissemination This protocol will not require ethical approval. The results of this review will be disseminated through peer-reviewed publications. Trial registration number CRD42019129014.