In a recent paper, Gray and Scott have considered the autocatalytic reactions: A + B: rate 0: ab", n = 0, I or 2 where II and b are the concentrations of A and B respectively. Interest centred mainly on irreversible systems but for which the catalytic species was not indefinitely stable, decaying instead by a rate proportional to its concentration b. fn practice all chemical reactions are to some extent reversible. The present work investigates the effect of reversibility for the cases in which B does not decay. Bounds are established on the ranges of residence-time t,,, for which multiple stationary-states are possible. The stability of the different solutions is assessed and the relaxation times t, characterizing the decay of perturbations are given. For deceleratory reactions FeWFSibility enhances the decay rates (decreases t*): for autocatalytic systems the decay rates may be unaltered or eveu reduced by a finite reverse reaction-rate. Also treated is the influence of non-zero inlet concentrations bo of the autocatalyst. This may lead to greater changes in the patterns of behaviour possible than those observed in the absence of reversibility. The algebraic analysis remains tractable throughout so the various effects can readily be