Investigated was the problem-solving ability of secondary school students as it related to their verbalization. Experimental treatment followed the students' demonstration of awareness of some mathematical concept. The four experimental groups included students who: (1) did not verbalize, (2) verbalized correctly, (3) verbalized incorrectly and were corrected, and (4) verbalized incorrectly and received no correction. After treatment, posttest scores were taken as measures of problem-solving ability. Experimental results showed no significant differences between experimental treatment groups, groups based on sex, or groups based on I.Q. (RS)