This study investigates the flow behaviour of Casson nanofluid over a stretching surface embedded in a porous medium, considering the effects of thermal radiation, Lorentz force, and particle diffusion. Key transport mechanisms such as thermophoresis, Brownian motion, magnetic field influence, and porous medium resistance are analysed to evaluate their impact on heat and mass transfer. The governing nonlinear differential equations for momentum, energy, and nanoparticle concentration are solved numerically using MATLAB’s bvp4c solver. The findings confirm that thermophoresis and Brownian motion significantly enhance nanoparticle dispersion and thermal conductivity, leading to improved Nusselt and Sherwood numbers. Additionally, thermal radiation and Lorentz force play a crucial role in modifying the fluid velocity and temperature distribution. These results align with previous studies and remain valid, reinforcing their applicability to various engineering and biomedical applications. The study's insights contribute to the advancement of heat exchangers, cooling devices, and nanofluid-based drug delivery systems, where precise control of heat and mass transfer is essential.