Nuclear properties of the excited states of Ar42 were measured by using the Ar40(t,pγ)Ar42 reaction at a bombarding energy of 2.9 MeV. Angular correlations of γ rays were measured using a spectrometer consisting of five NaI(T1) counters in time coincidence with an annular particle detector positioned about 180°. The analysis of these correlations yielded multipole-mixing and branching-ratio information for the electromagnetic deexcitations of Ar42 states, as well as spin assignments for some of the excited states. Coincident γ-ray spectra were also obtained using a Ge(Li) detector. Some of the measured excitations and spin assignments [Ex (kev); J] are: [1207±1.5; 2], [2414±5], [2485±3; 2], [2510±3], [3012±3; 1,2,3], [3092 ±3; 4], [3555±3; 2], [4004±5], [4123±4;≤2], [4285±5, 1,2,3], and [4629±5;≥1]. The results of this experiment are compared with recent shell-model calculations.