This study considered dynamic features of mixed convection flow over a vertical plate influenced by nonlinear thermal radiation and exponentially decaying internal heat generation. The importance of the nonlinear density variation with temperature (NDT) and convective heating is also analyzed. The governing equations are transformed into ordinary differential equations using the similarity variables and solved in MAPLE 2022 by a Runge–Kutta Ferhlberg fourth-fifth order scheme. The results obtained show that, with an increase in the convection process, the internal heat generation convects more fluid away and consequently reduced the rate of heat flowing back into the plate. For a weak internal heat generation , the plate temperature is less than one (1) and the heat is observed to flow from the plate into the fluid on the surface of the right plate. Furthermore, for weak convection and nonlinear thermal radiation effects, the rate at which the heat flows into the plate increases with the convective heat transfer parameter increase. However, for a strong nonlinear thermal radiation effect, the rate at which the heat flows out of the plate increases. The flow feature is not only governed by the rate of internal heat generation but the generation as well reverses the heat flow from the plate since the temperature of the near the plate surface is much higher than the environmental temperature .