The purpose of the article is to put forward English monologue production assessment criteria to verify the efficiency of the devised methodology of teaching English for future mechanical engineers. In the course of the research, theoretical, empirical, and statistical methods have been used. Various approaches to identifying the assessment criteria have been thoroughly analyzed. Seven criteria to assess the monologue production skills, five primary and two secondary ones, have been suggested. The allocation of the points by every criterion according to the devised scales have been elucidated. The proposed assessment criteria were used in the methodological experiment that was held at Igor Sikorsky Kyiv National Technical University. The experiment in question aimed to verify the efficiency of the devised methodology of teaching English monologue production to students majoring in mechanical engineering. Three experimental groups, 34 students in total, studying in their final year of Bachelor studies within the Subject Areas of Applied Mechanics and Industrial Engineering, participated in the methodological experiment. The conducted experiment confirmed the efficiency of the methodology proposed.