Background Patients with Down syndrome (DS) present functional and anatomical alterations that may negatively impact their health and quality of life. Down syndrome patients have been shown to have a high prevalence of temporomandibular disorder (TMD), but little is known about the diagnosis, treatment and prevention in these individuals. Objective To evaluate the impact of a home‐based multidisciplinary programme on muscular TMD in DS adults. Methods After being diagnosed with TMD‐related masticatory muscle disorder, 20 adult men and 20 adult women with DS received an educational material with instructions on how to perform daily home facial self‐massage and exercises for orofacial and masticatory muscles. Participants were also provided with educational information on TMD. Those who failed to perform at least 50% of the programme (23 days) were considered non‐adherent. Oral parafunctional behaviours, facial pressure‐pain threshold and maximum mouth opening were assessed at baseline and after the intervention. Results Twenty‐five patients adhered to the programme as opposed to 15 non‐adherent patients. Statistically significant improvements in all parameters were observed among adherent patients, except for the number of parafunctions. Conclusion The proposed home‐based multidisciplinary programme seemed to be effective in improving some aspects related to muscular TMD in DS adults.