The aim of this study is to reveal the feedback that secondary school science teachers provide for the student errors that show up during their lessons. Six different science teachers were observed throughout 90 sessions of science lessons for sixth and seventh grade in six different units as unstructured with this aim. The case study method was used within the study. Based on the data obtained from the study, feedback that the teachers provide for the students' errors was collected under 10 separate titles, and these titles are: 1. Saying just 'wrong', 2. Giving another student the right to speak, 3. Asking the question again, 4. Giving the answer directly, 5. Explaining the answer directly, 6. Investigating the reason for the mistake, 7. Correcting the incomplete or erroneous part of the answer, 8. Giving clues to student leading, 9. Repeating the answer of the student, 10. Ignoring the student answer. It was concluded from the study that science teachers most often make use of the third type feedback and least often use the last type. It is recommended that feedback provided for the mistakes should be systematically structured by conducting studies similar to this study in places which have different sociocultural structures and different class levels.