Control of photoinduced electron transfer through selective excitation of a pi-conjugated diblock oligomeric system featuring tetrathiophene (T-4) and tetra(phenylene ethynylene) (PE4) donor blocks capped with a naphthalene diimide (NDI) acceptor (T4PE4NDI) is demonstrated. Each pi-conjugated oligomeric segment has its own discrete ionization potential, electron affinity, and optical band gap which provides an absorption profile that has specific wavelengths that offer selective excitation of the PE4 and T-4 blocks. Therefore, T4PE4NDI can be selectively excited to form a charge-separated state via ultrafast photoinduced electron transfer from the PE4 segment to NDI when excited at 370 nm, but it does not produce a charge-separated state when excited at 420 nm (T-4). Picosecond transient absorption techniques were performed to probe the excited-state dynamics, revealing ultrafast charge separation (similar to 4 ps) occurring from the PE4 segment to NDI when excited at 370 nm, followed by delocalization of the hole over the T-4 segment. On the contrary, electron transfer is suppressed with excitation at longer wavelengths (>= 420 nm), where the spectrum is dominated by the T-4 unit. The rate of electron transfer and charge recombination was investigated versus the length of the PE bridge unit in oligomers featuring zero and two PE units (T4NDI and T4PE4 NDI). The rate of charge recombination decreases from 1.2 X 10(11) to 1.0 x 10(9) s(-1) with increasing bridge length between the T-4 and NDI components (T-4 NDI to T4PE4NDI). Furthermore, wavelength-dependent photoinduced electron transfer was not observed in either T4NDI or T4PE2NDI due to an insufficient PEn bridge length. This work demonstrates the ability to use optical wavelength to control photoinduced electron transfer in a fully pi-conjugated oligomer.