Excited-state properties of radical cations of substituted oligothiophenes (nT(center dot+), n denotes the number of thiophene rings, n = 3, 4, 5) in solution were investigated by using various laser flash photolysis techniques including two-color two-laser flash photolysis. nT(center dot+) generated by photoinduced electron transfer to p-chloranil or resonant two-photon ionization (RTPI) by using the first 355-nm ns laser irradiation was selectively excited with the second picosecond laser (532 nm). Bleaching of the absorption of nT(center dot+) together with growth of a new absorption was observed during the second laser irradiation, indicating the generation of nT(center dot+) in the excited state (nT(center dot+)*). The D-1 state lifetime was estimated to be 34 +/- 4, 24 +/- 2, and 18 +/- 1 ps for 3T(center dot+), 4T(center dot+), and 5T(center dot+), respectively. In the presence of hole acceptor (Q), bleaching of nT(center dot+) and growth of Q(center dot+) were observed upon selective excitation of nT(center dot+) during the nanosecond-nanosecond two-color two-laser flash photolysis, indicating the hole transfer from nT(center dot+)(D-1) to Q. Recovery of nT(center dot+) was also observed together with decay of Q(center dot+) because of regeneration of nT(center dot+) by hole transfer from Q(center dot+) to nT at the diffusion-limiting rate. It was suggested that the hole transfer rate (k(HT)) from nT(center dot+)(D-1) to Q depended on the free-energy change for hole transfer (-Delta G = 1.41-0.46 eV). The estimated k(HT) faster than the diffusion-limiting rate can be explained by the contribution of the static quenching for the excited species in the presence of high concentration of Q (0.1-1.0 M).