Our purpose in this paper is to provide an overview of what we know about alliance contracts. After a short introduction to the contents of alliance contracts, we start by contrasting alliance contractual form and governance form. Next, we focus on two related constructs: contractual complexity and contractual completeness. We suggest that contractual complexity is a more adequate construct to investigate in the absence of information about the transaction contemplated in the contract. After that, we present the measures of contractual complexity used in past studies. Then, we go over the determinants of contractual complexity by considering their influence on contracting costs and benefits given environmental and behavioral uncertainty. Conclusions and suggestions for research are offered at the end.