The current investigation communicates the characteristics of upper-convected second grade nanofluid thin film flow over a time-dependent stretching sheet with variable thermal conductivity and Cattaneo-Christov double diffusion theory. The mathematical model generates a system of nonlinear partial differential equations (PDEs) for heat, momentum, and mass transfer phenomena. Similarity variables converted the PDEs into nonlinear ordinary differential equations (ODEs). Furthermore, received ODEs are numerically rescued with the built-in program Bvp4c in MATLAB. The impact of physical parameters like second-grade fluid λ, unsteadiness parameter S, Prandtl number Pr, Schmidt number Sc, variable thermal conductivity ε, variable diffusivity ε 1 , the square of dimensionless film thickness γ, relaxation time δ e , and retardation time δ c are scrutinized. Tables revealed numerical exposure and graphs depict the geometrical aspect of the current study. The velocity field is improved by heightening the λ, magnification in temperature is found for greater conductivity parameter ε. Greater δ e in the temperature profile goes smaller. The rate of mass transfer diminishes by uplifting the estimations in relaxation time parameter δ . c