We propose several methods for the accurate determination of the cross sections of solid-state saturable absorbers and apply them to the analysis of polycrystalline ${\mathrm{Cr}}^{2+}:\mathrm{ZnSe}$ and ${\mathrm{Fe}}^{2+}:\mathrm{ZnSe}$ . In the case of ${\mathrm{Cr}}^{2+}:\mathrm{ZnSe}$ , both z-scan and power-dependent transmission measurements were made by using a continuous-wave fiber laser at $1800\mathrm{nm}$ and a pulsed optical parametric oscillator at $1570\mathrm{nm}$ . The average ground-state absorption cross sections at the wavelengths of 1800 and $1570\mathrm{nm}$ were determined to be $6.17\times {10}^{-19}{\mathrm{cm}}^2$ and $2.24\times {10}^{-19}{\mathrm{cm}}^2$ , respectively. Furthermore, the ratio of the cross sections at these wavelengths (2.75) was close to the value of 2.55 obtained from absorption spectrum measurements. Excited-state absorption was found to be negligible at both wavelengths. In the case of ${\mathrm{Fe}}^{2+}:\mathrm{ZnSe}$ , a tunable, pulsed ${\mathrm{Cr}}^{2+}:\mathrm{ZnSe}$ laser was used to obtain saturation data (z-scan and power-dependent saturation) at the wavelengths of 2645 and $2730\mathrm{nm}$ . Average ground-state absorption cross sections at 2645 and $2730\mathrm{nm}$ were determined to be $1.73\times {10}^{-19}{\mathrm{cm}}^2$ and $2.47\times {10}^{-19}{\mathrm{cm}}^2$ , respectively, again in very good agreement with those obtained from absorption spectrum measurements.