This paper describes an experimental study of the decay parameters and the magnetic moment of the Ξ-. A 1.8-GeV/c K- beam derived from the Bevatron was used to produce Ξ- by the reaction K-p-->Ξ-K+. The K+ and resulting decay products of the Ξ- were used to trigger a spark-chamber system, pictures from which yielded a total of 2724 events which passed all measuring criteria. The Ξ- were produced in an intense (170 kG) magnetic field obtained from a pulsed magnet. The precession of the magnetic moment of the Ξ- in the presence of this field can be measured from the angular distribution of the Ξ- decay products and a value of the magnetic moment obtained. The decay parameters and polarization of the Ξ- are also obtained from the angular distribution of the decay products; we obtain α=-0.383+/-0.065, Φ=-(26+/-30)°, and P̄=0.19+/-0.09. The accuracy of the magnetic moment value is severely limited by the low value of polarization and experimental biases in the distribution; we obtain μΞ-=-0.1+/-2.1 nuclear magnetons.