On the basis of coupled kinetic/power-balance calculations, we examine the degree of recoil tail creation due to nuclear elastic scattering and its effect on the fusion reactivity of self-sustaining D-3He plasmas. It is shown that at a typical operating state (e.g. Tibulk = 100keV), the d–d [d–t] reaction rate parameter increases by 10–20% [decreases by ≤ 10%] from the values for Maxwellian distributions, while the d–3He reaction remains almost unchanged.