  We study the |Delta I|=3/2 amplitudes of the octet-hyperon decays B -> B' +
pion and of the decays Omega^- -> Cascade + pion in the context of heavy-baryon
chiral perturbation theory. For the octet-hyperon decays, we investigate the
theoretical uncertainty of the lowest-order predictions by calculating the
leading non-analytic corrections. We find that these corrections are within the
expectations of naive power counting and, therefore, that this picture can be
tested more accurately with improved measurements. For the Omega- decays, we
obtain at leading order two operators responsible for the decays which also
contribute at one loop to the octet-hyperon decays. These one-loop
contributions are sufficiently large to suggest that the ratio of measured
widths of Omega^- -> Cascade0 + pion- to Omega^- -> Cascade- + pion0 being
approximately equal to 2.7 may be too large.
