The two‐photon absorption (TPA) coefficient has been measured for a single‐mode GaAs/AlGaAs quantum well laser at 0.86 &mgr;m, near the lasing wavelength of 0.83 &mgr;m. Picosecond laser pulses were employed to resolve the ultrafast TPA from long‐lived carrier‐dependent effects. The TPA coefficient was found to be 31±6 cm GW−1, which corresponds to a value of (5.7±1.2)×10−11esu for the imaginary part of the third‐order nonlinear susceptibility. At wavelengths near the quantum well exciton, no strong resonance enhancement of the two‐photon transition was observed, and the coefficient appears to be characteristic of the AlGaAs cladding layers.