The aim of this study was to examine the effects of critical thinking (CT) teaching involving general, immersion, and mixed approaches on the CT skills and dispositions of high-school students. The study, which had three experimental groups (EG) and one control group, employed a pretest--posttest control-group quasi-experimental design. CT teaching was initiated with a general approach in EG I, an immersion approach in EG II, and a mixed approach in EG III. The Critical Thinking Skill Test and UF/EMI Critical Thinking Disposition Instrument were used to collect the data. General, immersion, and mixed approaches improved CT skills and dispositions, with a large effect size for the improvement of CT skills. CT teaching with general, immersion, and mixed approaches had large, moderate, and small effects, respectively, on improving CT dispositions. In terms of improving CT skills and dispositions, the most effective approach, respectively, was the general, mixed, and immersion approach.