In French and Spanish, both parts of the causative–anticausative alternation can be formally encoded in two ways: Depending on the form of the verb, marked and unmarked causatives and marked and unmarked anticausatives can be distinguished. The goal of this paper is to verify whether causalness is a factor in the encoding and whether the two languages differ in this respect (verbs used more often as causatives than as anticausatives have a high degree of causalness, while verbs used more often as anticausatives than as causatives have a low degree of causalness). On the basis of a corpus study of 20 French and 20 Spanish verbs, it will be shown that in both languages a strong correlation between causalness and encoding exists. A high degree of causalness increases the likelihood that a verb’s anticausative is marked and the causative is unmarked, and a low degree of causalness increases the likelihood that a verb’s anticausative is unmarked and the causative is marked.