Absorption and photoinduced absorption (PIA) spectra of thin films of polycarbazolyldiacetylenes carrying alkyl (polyDCHD-HS) or acyl (polyDPCHD) substitutions are reported. The absorption spectra are dominated by an excitonic absorption followed by a vibronic progression, and are quite insensitive to the temperature. The PIA spectra show the typical spectral feature of a triplet excitation whose rise and decay times are different. The PIA signal shows a strong sublinear pumping intensity dependence, which also affects the rise time.