This paper deals with the effects of thermal radiation on unsteady MHD nanofluid flow past a stretching sheet with non-uniform heat source/sink. The flow and heat transfer characteristics are analysed for aluminum oxide (Al2O3) and titanium dioxide (TiO2) nanoparticles with water as a base fluid. The governing time-dependent partial differential equations are transformed into ordinary differential equations by similarity transformations. Runge-Kutta fourth order method together with shooting technique has been employed for the solutions of the differential equations. The impact of different flow parameters namely, unsteadiness parameter, magnetic field parameter, volume fraction parameter, radiation parameter and non-uniform heat source/sink parameters are illustrated and discussed graphically. It is noticed that the nanoparticle volume fraction parameter ϕ shows opposite effect on the fluid velocity and temperature distributions. Subsequently the comparison with the previously published results for steady flow is excellent. This model finds important applications in studying heat transfer enhancement in the renewable energy systems and in material processing. © 2017 by American Scientific Publishers All rights reserved.