The excited state absorption and optical limiting of a series of platinum(II) 4'-arylterpyridyl acetylide complexes have been investigated. These complexes possess relatively long triplet excited state lifetime that varies from tens of nanoseconds to several microseconds; and exhibit broad triplet excited state absorption in most of the visible to near infrared spectral region. Nonlinear transmission experiments demonstrate that all of the complexes show pronounced optical limiting for ns laser pulses at 532 nm. The photophysical properties and optical limiting characteristics are influenced significantly by the nature of 4'-aryl substituent and the acetylide ligand.