Background: The condition known as forward head posture occurs when the head is positioned in front of the trunk and protrudes forward in the sagittal plane of the cervical vertebrae. As a result, the head's structural center shifts forward and upward, putting a greater load on the cervical vertebrae. Aim of the study: To investigate the impact of adding cervical & thoracic spinal mobilization techniques to deep cervical training compared to deep cervical training alone on Deep Neck Core Strength & Craniovertebral angle (CVA). Methods: Sixty-Six patients from both sexes with forward head posture, with age range from 18-25 years was randomly assigned to 3 groups. It was conducted between June 2022 and December 2022. The ethical committee number is: P.T.REC/012/003524 registered by the faculty of physical therapy, Cairo university. Group (A) received deep cervical training; Group (B) received deep cervical training + upper cervical mobilization & Group (C) received deep cervical training + upper thoracic mobilization. Mean readings for CVA, deep neck flexor strength, were analyzed using a mixed MANOVA to examine the effect of time, the impact of treatment, in addition to the interaction of time and treatment. for the possibility for multiple comparisons in the results, post-hoc testing utilizing the Bonferroni correction were performed. Results: Pre-treatment comparisons showed no statistically significant differences between the groups. Groups B and C showed statistically significant improvements in CVA as well as deep neck core strength post-treatment in comparison with group A (p < 0.05). When comparing groups B and C, the results showed no significant difference in CVA as well as deep neck core strength (p > 0.05). Conclusion: Combination of deep cervical training & mobilization techniques for the upper cervical and thoracic region had a significant effect on improving the neck core stability and CVA comparing to the deep cervical training only.