Two-dimensional double-diffusive convective flow in a duct is studied numerically. The duct is filled with electrically conducting nanofluid and subjected to mutually orthogonal static electric and magnetic fields. The one-phase Tiwari–Das model is employed to simulate nanoscale effects. The study is conducted for four different electroconductive nanofluids using water as a base fluid. The left and right plates of the enclosure are kept at different constant temperatures and concentrations. The top and bottom faces are insulated and impermeable to heat and mass trans-fer, respectively. The transport equations describe the velocity, temperature, and nanoparticle concentration fields. These coupled differential Navier–Stokes equations are nonlinear and therefore discretized via a robust finite difference method (FDM). The reduced difference equations are solved by incorporating the successive-over-relaxation (SOR) method. The results are shown graphically for various governing parameters. The skin friction, Nusselt and Sherwood numbers for the impact of selected electromagnetic, nanoscale, and thermophysical parameters are com-puted. The study is relevant to thermal power technologies, bioelectromagnetic therapy, and nu-clear engineering heat transfer control. © 2021 Begell House, Inc. www.begellhouse.com.