Biology course can be difficult for students at times as it includes a lot of concepts and a relatively intense content. At this point, students’ attitude towards biology and biology course is highly important because having developed a positive attitude would significantly affect behavior. In other words, those students who have developed a positive attitude towards biology and biology course are expected to be more interested in class, more enthusiastic for learning, and as a result more successful. In this research, the gender and grade level variables as well as the pet-keeping variable were examined. The effects of these variables on the attitudes of secondary school students towards biology and biology course were examined by MANOVA. The sample of the research, which was designed in a relational survey model, consisted of 1047 secondary school students. In the collection of data, “Secondary School Students’ Attitude towards Biology and Biology Course Scale” was used. It was concluded that students who keep a pet have a more affirmative attitude. It was determined that female students have a more affirmative attitude compared to male students and 9th graders have a more affirmative attitude compared to students in other grade levels. Finally, it has been discussed why female students', pet keeping students' and lower grade students' attitudes towards biology and biology course are more affirmative, and suggestions for increasing students' attitudes have been developed. Keywords: attitude towards biology, biology course, secondary school students, pet-keeping behavior.