Mathematical analysis for magnetohydrodynamic (MHD) nonlinear convective flow of Walter-B nano fluid over a nonlinear stretching sheet with variable thickness is introduced. Heat transfer phenomenon is based through involvement of nonlinear thermal radiation and heat generation/absorption. Intention in present analysis is to develop a model for nanomaterial comprising Brownian motion and thermophoresis phenomena. Boundary layer approximation is applied to partial differential equations. Governing equations are then converted into ordinary differential equations by invoking appropriate variables. The transformed expressions are explored through homotopic algorithm. Plots for velocity, temperature and concentration fields are presented and their behavior is deliberated for several sets of values of governing variables. Skin friction coefficient and local Nusselt number are inspected through numerical values. It is concluded that viscoelasticity reduces the velocity field while reverse situation is observed due to wall thickness parameter. Thermal field and heat transfer rate are enhanced for temperature ratio parameter. Moreover effect of Brownian motion and thermophoresis parameter are quite reverse for the concentration field. (C) 2017 Elsevier Ltd. All rights reserved.