This paper aims to present the analysis of transient wave characteristics in a functionally graded viscothermoelastic infinite medium with spherical cavity in the context of generalized thermoelasticity. Continued series solution is used to solve simultanious differential equations for evaluating the field variables. Convergence of the series solution is implemented and investigated that the series of functions are absolutely and uniformly convergent. The formal solution for the field variables are obtained analytically and represented graphically. The effect of grading index and different theories of generalized thermoelasticity are also shown graphically to examine the behavior of the variations of the field variables. © 2020, Springer-Verlag GmbH Germany, part of Springer Nature.