Guillaume van Baalen Alain Schenkel Peter Wittwer Asymptotics of solutions in $nA+nB\to C$ reaction-diffusion systems (282K, LaTeX2e with 1 PS Figure) ABSTRACT. We analyze the long time behavior of initial value problems that model a process where particles of type $A$ and $B$ diffuse in some substratum and react according to $nA+nB\rightarrow C.$ The case $n=1$ has been studied before; it presents nontrivial behavior on the reactive scale only. In this paper we discuss in detail the cases $n>3,$ and prove that they show nontrivial behavior on the reactive and the diffusive length scale.