This quantitative study reports the effects of gender and grade level on secondary students’ attitude towards chemistry lessons. For this purpose, the Attitude towards Chemistry Lessons Scale (ATCLS) was administered to 446 secondary school students between 16-19 years old. The ATCLS consists of four different subscales: liking for chemistry theory lessons, liking for chemistry laboratory work, evaluative beliefs about school chemistry and behavioral tendencies to learn chemistry. Data obtained from the ATCLS survey was analyzed using two-way MANOVA to identify the effects of gender and grade level on students’ attitude towards learning chemistry. The findings show that gender and grade level have a significant effect on attitude towards learning chemistry. Gender and grade level also have a significant interaction effect (Wilks’ lambda = 0.933, F (15, 1198) = 2.032, p < 0.05) on secondary school students’ attitudes towards chemistry.