Three ruthenium-based complexes exhibiting catalytic activity in olefin metathesis have been examined for the presence of interesting nonlinear optical (NLO) properties. Measurements were performed by the Z-scan technique using a tunable femtosecond laser system. This initial screening for potential new applications in photonics of complexes representative of a wide family of ruthenium-based olefin metathesis catalysts has found moderately strong two-photon and three-photon absorption properties in relatively simple molecules that may lead to the development of a new class of strong nonlinear absorbers.