Background <p>Rehabilitation is very crucial for the treatment of chronic illnesses; it is still not widely used in primary healthcare in low-resource countries like Pakistan. Although there is ample evidence of gaps in the health system, behavioural factors that influence provider engagement with rehabilitation services remain poorly understood, especially regarding attitudes, social influences, and a sense of control over service provision. This study investigated how providers’ attitudes, societal expectations, and perceived control affected their engagement in a rehabilitative health system-strengthening initiative in Pakistan using the Theory of Planned Behavior (TPB).</p> Methods <p>This qualitative exploratory study was a sub study of ReLAB-HS initiative, which sought to incorporate assistive technology and rehabilitation services into primary care. Data was collected between July and August 2024 from two Networks of Care (Thatta and Swat) from the two provinces Sindh and Khyber Pakhtunkhwa. Participants (<i>n</i> = 61) were among the five cadres and purposefully chosen, including Lady Health Workers, Lady Health Supervisors, Primary Healthcare Providers, Rehabilitation Professionals, and members of Technical Working Group Data were analyzed using a combined inductive–deductive approach guided by the Theory of Planned Behavior (TPB), with coding and theme development conducted in Atlas.ti.24.</p> Results <p>Interviews revealed that providers’ attitudes shifted from initial skepticism to recognizing rehabilitation as a crucial part of primary care, particularly after observing improvements in patient functioning. Subjective norms, reinforced through peer support and digital platforms such as WhatsApp, played a key role in sustaining engagement, although broader uptake was constrained by cultural norms and gender-related stigma. Perceived behavioral control improved with training and job aids, increasing providers’ confidence to integrate rehabilitation into practice. However, persistent structural and environmental barriers including time constraints, heavy workloads, and limited access to assistive technology reduced providers perceived behavioral control and restricted sustained implementation. Despite these challenges, many providers adopted adaptive strategies to continue delivering rehabilitation services.</p> Conclusion <p>Our findings demonstrate that attitudes, subjective norms, and perceived behavioral control collectively shaped provider engagement with rehabilitation services. Peer networks, supportive supervision, and capacity-building initiatives facilitated positive behavioral change; however, these alone were insufficient for long-term integration at the primary care level. Addressing structural barriers including weak referral systems, limited assistive technology, workforce shortages, and sociocultural stigma is essential for sustainable rehabilitation integration.</p>