Experimental measurements of optical limiting resulting from reverse saturable absorption in metallo-phthalocyanine and metallo-naphthalocyanine compounds are reported. Open aperture ns z-scan with Gaussian pulses are employed to investigate the interaction of high intensity light with the novel compounds. Rate equations are used to analytically solve the static state solution that simulates the excited state dynamics resulting from the nonlinear excited state absorption, and this is fitted to the experimental data. General molecular engineering trends relating the optical limiting performance of these compounds to their structural characteristics are explored and discussed.© (2003) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.