The laser fluorescence excitation spectrum of the ArBH van der Waals complex, in the vicinity of the A (1) Pi - X (1) Sigma(+) (0,0) band of diatomic BH, is reported. This species was prepared in a pulsed free jet by 193 nm multiphoton dissociation of diborane seeded in Ar/He. Both rotationally resolved and diffuse bands of the ArBH complex were observed. Rotational analyses were carried out for most of the sharp bands; both perpendicular [P’=1<--P"=0] and parallel [P’=0<--P"=0] transitions were found. The assignment of the bending and van der Waals stretch vibrational quantum numbers were carried out with the help of the accompanying paper [M. H. Alexander, S. Gregurick, and P. J. Dagdigian, preceding paper, J. Chem. Phys. 101, 2887 (1994)], wherein ArBH(A,X) ab initio potential energy surfaces, and subsequently vibrational energies, are calculated. The pattern of ArBH(A) vibrational energies was found to be complicated, mainly because of the large difference in the Ar-BH(A) interaction energy when the unpaired pi electron is in or perpendicular to the triatomic plane.