This study aims to teach the relationship between metabolic rate and oxygen consumption to pre-service science teachers by using the POE strategy. Among the qualitative research methods, the case study design was used. The study sample consisted of 32 pre-service science teachers from a university's faculty of education department of science education, who took the course "General Biology Laboratory". A work sheet titled "Oxygen Consumption of Animals" prepared based on the Predict-Observe-Explain (POE) strategy was used for data collection. The data was analyzed using frequencies (f) and percentages (%). At the end of the study, 95.3% of the participants were found to be actively involved in the prediction step. It was also found that all of the participants made observations and expressed their reasons, while 98.5% participated in the explanation step. These findings reveal that pre-service science teachers tend to be actively involved in all steps when such kind of teaching strategy is presented to them.