The paper discusses asymptotic stability conditions for the linear fractional difference equation ∇ α y(n) + a∇ β y(n) + by(n) = 0 with real coefficients a, b and real orders α > β > 0 such that α/β is a rational number. For given α, β, we describe various types of discrete stability regions in the (a, b)-plane and compare them with the stability regions recently derived for the underlying continuous pattern D α x(t) + aD β x(t) + bx(t) = 0 involving two Caputo fractional derivatives. Our analysis shows that discrete stability sets are larger and their structure much more rich than in the case of the continuous counterparts.MSC 2010 : Primary 34A08, 39A12; Secondary 39A30, 26C10