To provide an insight into the optical limiting (OL) behavior of a series of 3 metallated 1,4,8,11,15,18,22,25-octaalkylphthalocyanines; the third-order nonlinear optical (NLO) properties, one-photon absorption (OPA) and two-photon absorption (TPA) characterizations have been theoretically investigated by means of AMI, ZINDO and configuration interaction (CI) methods. The highest values for the TPA cross-section (δ(ω)) are exhibited by derivatives metallated with indium and lead. It is also seen that the nickel-metallated compound might be a passive optical limiter of the series, indicating the weakest δ(ω) and second hyperpolarizability (γ). Our calculated results are in good agreement with the previous experimental observations on the examined molecules. © World Scientific Publishing Company.