We study the properties of the reaction front formed in a reversible reaction-diffusion process, A+B?kgC, with initially separated reagents. It is shown that the dynamics of the front can be described in terms of a crossover between ‘‘irreversible'' scaling at short times (t≪g−1) and ‘‘reversible'' scaling at long times (t≫g−1). The reversible regime is dominated by diffusion and the critical exponents characterizing the properties of the front are independent of dimension.