In mathematics education, teachers can use several reasoning methods to find solutions such as inductive, deductive and analogy. This study was intended to guide students to find solutions to problems of radical inequalities through analogical reasoning. The experiment was conducted on 36 grade 10 students at a high school in Can Tho city of Vietnam. The instrument used was a problem of radical inequalities. A three-phase teaching process had been organized with this class comprising individual work phase, group work phase and institutionalization phase. The data collected included student worksheets and was qualitatively analyzed. As a result, many students discovered how to solve the above inequality by using the analogy, and they had a considerable improvement in their problem-solving skills. Additionally, a few ideas were discussed about the use of analogy in mathematics education