An existing renormalization approach of the strong fluctuation theory is extended to cover a general bi-isotropic random medium with spherically symmetric correlation functions. The effective random-medium parameters for long wavelengths are expressed in terms of a background medium's parameters and the spectral densities or correlation functions of random perturbations. A validity range of the results obtained is determined, and the particular cases of reciprocal bi-isotropic, Tellegen, isotropic, and lossless bi-isotropic random medium are analyzed.