Background/Purpose: The present study aimed to determine the immediate effect on cervicogenic headache by primal reflex release technique (PRRT)TM on rectus capitis posterior muscle. Objective: To determine the effects of primal reflex release techniques on the Rectus capitis posterior muscle in cervicogenic headache. Methodology: 46 patients were examined according to the inclusion and exclusion criteria and randomly divided into experimental group and conventional group. Outcome measure including VAS, Cervical Rotation, NPDS, NDI and HDI were assessed prior to the intervention. Experimental group received primal reflex release technique which includes rectus capitis posterior muscle. Conventional treatment group received hot packs, stretching and cervical isometric. Post intervention assessment was done to assess immediate changes in subjects of both group for assessing immediate effects of treatment protocol. Result: The study compares data from five outcome measures to assess the effectiveness of Primal Reflex Release Technique (PRRT) on cervicogenic headache. Results show that both PRRT and conventional therapy have similar effects on cervicogenic headache. Conclusions: This study found positive changes in all outcome measures (VAS, cervical rotation, NPDS, HDI, and NDI) from pre- to post-intervention in both groups receiving either PRRT or conventional therapy for cervicogenic headache with rectus capitis posterior muscle involvement.