Monte Carlo calculations have been made of the sensitivity of a 200 cm3 intrinsic germanium detector, guarded by a large NaI(Tl) Compton suppression annulus, for the observation of the hypothesized neutrinoless double beta decay of 76Ge. It was assumed apriori that the background levels would be similar to those achieved by Fiorini and his co-workers in the original experiment. It was determined, for example, that an annulus 51 cm in diameter and 61 cm long, would suppress the continuum background in the vicinity of the 2.045 MeV neutrinoless double beta decay peak, so as to allow the observation of a decay with a half-life of 2.6 × 1025 y. © 1979.