This study examines written comments of nonnative-speaking teachers of English and native-speaking teachers of Spanish on undergraduate theses of nonnative-speaking students of English and native-speaking students of Spanish. The aim of the study was to analyze the characteristics of the feedback provided applying the categories of corrective and genre oriented types of comments, and to study whether these types of comments vary through the thesis drafts. This is a descriptive qualitative study with quantitative aspects and an exploratory scope. The material was collected from the dialogic cycle of receiving and providing feedback during the students’ thesis writing process. 1241 written comments were analyzed. The results showed that genre comments were more abundant in theses written in Spanish than in those written in English. However, Spanish teachers also provided more corrective comments than English teachers did.