Promoting students' critical thinking (CT) in writing classes gained attention in the education system following the requirement of students' CT ability in academic writing, particularly in higher education. The study sought to uncover how instructors promote students' CT in writing classes as perceived by university students and students' CT performance in writing. The participants were 330 first-year university students selected from Wolkite University using a stratified sampling technique. A questionnaire of Students' Perceptions of the Promotion of CT in Writing (SPPCTW) and essay writing were used to generate data. The data analysis included descriptive statistics, spearman rho correlation, and multiple regression. The findings revealed that instructors utilized some particular CT stimulating strategies. These included allowing students to work collaboratively, make arguments, and examine the role of different expressions, words, and ideas before writing. They allowed students to perform argumentative and expository writing activities through the process approach. Contrarily, the students reported limited chances to challenge instructors' perspectives, generate ideas from different sources, and do self-reflection. The result further indicated a positive and statistically significant relationship between the students' perceptions of instructors' promotion of CT in writing classes and students' CT performance in writing. Besides, the three factors (CI, IM, and NWA) had a statistically significant and positive impact on students' CT performance in writing. Yet, the impact of SFP was negative and not statistically significant. These findings could provide insights to different concerned bodies in the English language teaching field.