The purpose of the present paper is to elicit the effects of reflective thinking-based teaching activities on pre-service teachers' reflective thinking skills, critical thinking skills, democratic attitudes, and academic achievement. The paper employed experimental design. The study group consisted of second year students from the Education Faculty of Gazi University in the 2010-2011 academic year. In total, 42 students (21 experimental; 21 control) were selected. Data were collected from: 1) California Critical Thinking Scale, 2) Democratic Attitudes Scale, 3) Academic Achievement Test,, 4) Reflective Thinking Tendency Scale for Teachers and Pre-service Teachers, 5) Reflective Journal, and 6) Rubric for portfolio.Though the experimental group obtained higher post-test, achievement, reflective thinking, critical thinking, democratic attitude, and academic achievement mean scores than the control group, these differences were found to be statistically not significant. The students were able to perform the behaviors required by reflection-on-action and reflection-in-action processes to a great extent.