Introduction: Manual therapy has been shown to reduce self-reported symptoms in patients with chronic tension-type headache (CTTH). However, simultaneous application of suboccipital muscle inhibition and interferential current has not previously been investigated. This study evaluates the effectiveness of combined treatment with suboccipital muscle inhibition and interferential current compared to standard treatment for pain, disability, and headache impact in patients with CTTH., Methods: Patients were randomly allocated to receive either standard treatment (n = 13) or the experimental treatment (n = 12), consisting of 20 minutes of suboccipital muscle inhibition plus interferential current twice weekly for 4 weeks. The primary outcome was improvement in pain, and secondary outcomes included improvement in headache-related disability and reduction in headache impact, which were assessed at baseline and at 4 weeks by a blinded rater., Results: Statistical analysis showed improvements in the experimental treatment group at 4 weeks for headache-related disability (Neck Disability Index: Hedges' g = 1.01, P = .001; and Headache Disability Inventory: Hedges' g = 0.48, P = .022) and headache impact (6-item Headache Impact Test: Hedges' g = 0.15, P = .037) but not for self-reported pain (numerical rating scale: Hedges' g = 1.13, P = .18)., Conclusions: Combined treatment with suboccipital muscle inhibition and interferential current in patients with CTTH did not significantly improve self-reported pain but did reduce disability and the impact of headache on daily life at 4 weeks. These improvements exceed the minimum clinically important difference, demonstrating the clinical relevance of our findings., (Copyright © 2020 Sociedad Española de Neurología. Published by Elsevier España, S.L.U. All rights reserved.)