Objective:

This research aims to study peer tutoring focused on academic writing to categorize and describe the strategies that a group of tutors from a private Latin American university employs to support students' academic literacy development.

Method:

We conducted a qualitative diary study, in which we analyzed 203 diary entries from 13 tutors, following the constant comparative analysis method proposed by grounded theory.

Results:

Eleven categories emerged from data that can be grouped into two major categories: collaborative writing strategies and strategies for the development of metacognition in writing.

Conclusions:

We described and categorized diverse tutorial strategies that can be explicitly taught during tutor training programs to promote the development of academic writing skills in less advanced students.