This paper studies the impact of contract duration in determining scheduled payments in international transfers of technology. Analyzing a sample of contracts written by Spanish firms in 1991, the main empirical finding is a positive relationship between contract duration and the probability of the parties including variable payments in the first period of the agreement. This result suggests that the parties choose the type of payments to be made, whether fixed or variable, so as to avoid early termination of the relationship, even in the absence of opportunistic behavior or risk aversion.