This study aimed to investigate the correlation between: (1) critical and creative thinking skills; (2) critical thinking skills and learning achievement; (3) creative thinking skills and learning achievement; and (4) critical thinking, creative thinking, and learning achievement. The current study was conducted in April 2019 and employed a correlational research design. The participants of this study consisted of 30 four-semester students from the Department of Biology Education of IKIP Mataram, Indonesia who were currently studying Plant Physiology. Data were collected using a test which contained 19 essay questions on photosynthesis. The critical thinking instrument was composed of five aspects that measured the participants’ ability to apply, evaluate, use data to develop critical insights, analyze, and synthesize information, whereas the creative thinking instrument comprised of eight aspects that include curiosity, fluency, originality, elaboration, flexibility, divergent thinking, messiness/risk taking, and collaborative working. In addition, the instrument used to determine learning achievement incorporated six aspects: remembering, understanding, applying, analyzing, evaluating, and creating. Each of the aspects was represented by one test item. The results of the data analysis indicated correlations between: (1) critical and creative thinking skills; (2) critical thinking skills and learning achievement; (3) creative thinking skills and learning achievement; (4) creative thinking, critical thinking, and learning achievement. Since critical and creative thinking skills have an effect on learning achievement, the empowerment of these skills may lead to the enhancement of learning achievement.