This paper presents an analytical framework to establish finite gain stability for nonlinear interconnected mixed passive and negative imaginary systems. The stability analysis is presented using the notation of dissipitivity. The proposed stability framework enables us to extend the number of existing results from the linear mixed systems to the wide range of nonlinear mixed systems. Accordingly, the stability analysis of this paper extends the work of Das et al. (in: 2013 Australian control conference. IEEE, pp 445–449, 2013) to nonlinear cases. A numerical example is presented in the paper to test the results of the proposed analytical framework.