The triplet saturable absorption behaviour of the xanthene dyes eosin Y, erythrosin B, and rose bengal and of the fullerene molecule C 70 is studied. The molecules are excited to the S 1-state by intense picosecond pulses (wavelength λ P=527 nm). They relax dominantly to the triplet system by intersystem crossing. The triplet–triplet saturable absorption is investigated with time-delayed intense picosecond pulses (wavelength λ L=1054 nm) in the transparency region of the molecules in the singlet ground state. Higher excited-state triplet absorption cross-sections and higher excited-state triplet relaxation times are determined by numerical simulation of the experimental results. Time-resolved fluorescence measurements reveal higher excited-state triplet to singlet back-intersystem-crossing and multi-step triplet photoionization. Additionally the two-photon absorption cross-sections at λ L=1054 nm are determined by measurement of the fundamental pulse two-photon induced fluorescence relative to the second-harmonic pulse single-photon induced fluorescence.