Pharmaceutical marketing through financial incentivisation to general practitioners (GPs) is a poorly studied health system problem in Pakistan. Pharmaceutical incentivisation is seen to be distorting GPs prescribing behaviour that can compromise the health and well-being of patients. We draw on a conceptual framework outlined in the ecological system theory to identify multiple factors linked with pharmaceutical incentivisation to GPs in Pakistan. We conducted qualitative interviews with 28 policy actors to seek their views on the health system dynamics, how they sustain pharmaceutical incentivisation and their effect on the quality of care. Our analysis revealed four interlinked factors operating at different levels and how they collectively contribute to pharmaceutical incentivisation. In addition to influences such as the increasing family needs and peers' financial success, sometimes GPs may naturally be inclined to maximise incomes by engaging in pharmaceutical incentivisation. On other hand, the pharmaceutical market dynamics that involve that competition underpinned by a profit-maximisation mindset enable pharmaceutical companies to meet GPs' desires/needs in return for prescribing their products. Inadequate monitoring and health regulations may further permit the pharmaceutical industry and GPs to sustain the incentive-driven relationship. Our findings have important implications for potential health reforms such as introducing regulatory controls, and appropriate monitoring and regulation of the private health sector, required to address pharmaceutical incentivisation to GPs.