Recent studies on metal dithiolene complexes in solution and PMMA have shown this range of materials to exhibit high third-order nonlinear optical coefficients, (Chi) 3, and excellent figures of merit. Phthalocyanine dyes have been shown to exhibit optical limiting due to the nonlinear effect of reverse saturable absorption. We report here on the third-order nonlinear optical characterization of several metal dithiolene and phthalocyanine compounds doped in sol-gel derived materials. These hosts provide a physically and chemically stable environment for the nonlinear compounds, and offer the potential of high levels of doping. The dithiolene and phthalocyanine compounds were incorporated into partially densified sol-gel silica glass (xerogels) by the post-doping technique, and into the hybrid organic-inorganic materials at the sol-stage. To obtain optical quality surfaces on the porous xerogel, a unique polishing technique has been developed. Picosecond and nanosecond pulsed laser studies of nonlinear refraction and absorption are presented, together with laser damage and micro-hardness measurements. For the dithiolenes, concentrations of the order of 1018 molecules/cm3 for both the hybrid material and the xerogel were studied using the degenerate four wave mixing (DFWM) technique. (Chi) 3 values up to 1.4 X 10-19 m2/V2 (equivalent to 1.0 X 10-11 esu) were observed in the sol-gel host.