We address the problem of automatic synthesis of decision procedures. We evaluate our ideas on ground arithmetic and linear arithmetic, but the approach can be applied to other domains as well. The approach is well-suited to the proof-planning paradigm. The synthesis mechanism consists of several stages and sub-mechanisms. Our system (adeptus), which we present in this paper, synthesized a decision pro- cedure for ground arithmetic completely automatically and it used some specic method generators in generating a decision procedure for linear arithmetic, in only a few seconds of cpu time. We believe that this approach can lead to automated assistance in constructing decision procedures and to more reliable implementations of decision procedures.