The purpose of this study is to examine motivation of science high school students towards learning biology and their attitude towards biology lessons. The sample of the study consists of 564 high school students (308 females, 256 males) studying at two science high schools in Aksaray, Turkey. In the study, the relational scanning method, which is a descriptive scanning model, was utilized, with data obtained using the "Academic Motivation Scale for Learning Biology", consisting of four subdimensions (intrinsic motivation, amotivation, extrinsic motivation-career and extrinsic motivation-social) and 19 items, and the "Biology Science and Course Attitude Scale", consisting of three subdimensions (interest, pleasure and anxiety) and 23 items. Data were interpreted in accordance with arithmetic mean, percentage, frequency and significance levels. The significance level was taken as 0.05. As a result of the research, the arithmetic means of students' intrinsic motivation and extrinsic motivation-career subdimensions were found to be above the scale mean. Students' mean score in the amotivation and extrinsic motivation-social subdimensions were below the scale mean. However, in each of the subdimensions on the attitude scale, students' arithmetic means were average. The highest relation among the subdimensions of the motivation and attitude scales was found to be between the intrinsic motivation and interest subdimensions and the intrinsic motivation and pleasure subdimensions. Nevertheless, as a result of the evaluation conducted in terms of students' gender and class level, it was determined that there was a significant difference between their gender and class levels in the subdimensions of motivation and attitude scales.