The study aimed to determine science lesson-focused responsibility levels of primary school students in terms of various demographic variables. This study used a quantitative research methodology and a descriptive survey model, one of the general survey models. The research was conducted in three central districts in Kayseri province, Türkiye, in the 2018-2019 academic year. The research sample included 705 pupils. The study collected data through the "Science Lesson-Focused Pupil Responsibility Scale" developed by the researchers. Scales' Cronbach Alpha internal consistency coefficient is 0.87 and the scale explains 50.83% of the total variance. Results of the study revealed that the children's science lesson-focused responsibility levels differed significantly in favour of female students (U=53495.5; p<0.05). Furthermore, lesson-focused responsibility levels differed significantly in favour of third-grade pupils. They differed significantly in favour of "those who like the lesson very much" according to interest level in the science lesson (U = 43331.0; p <0.05). However, they did not vary by birth order (X[superscript 2][subscript (3)] =0.236; p> 0.05), the number of siblings (X[superscript 2][subscript (3)] = 1.140; p>0.05), preschool experience (U = 24494.0; p>0.05), or the educational level of parents (U = 24494.0; p>0.05). Based on the results, boys can be assigned tasks in which they can take responsibility within the scope of daily life and science lessons, and studies that increase their level of responsibility can be carried out. In addition, the contents of the science course curriculum and textbooks can be enriched by including activities based on practices that increase learner curiosity and interest levels.