The close association between science and masculinity has been widely discussed, yet few studies have focused on boys' negotiation with, and participation in, school science. This paper seeks to trouble monolithic notions of the link between science and masculinity, arguing that the "ideal science student" is a classed, racialized, and gendered construction. Drawing on interviews, observations, surveys, and student work samples, we construct longitudinal case studies of four scientifically talented boys from fourth to sixth grades, showing how "being smart" is a necessary, but not sufficient, requirement for boys who want to position themselves or end up getting positioned as "scientific." We also demonstrate how "being interested in science" is a useful, but not essential, component of these boys' identity performances and recognition work. We explain how the boys take up different positions in relation to the "smart science boy" subject position (the "smart boy," "smart science boy," "wannabe smart science boy," and "geeky science boy") and argue that the boys' in/ability to authentically inhabit the "ideal science student" subject position is constrained and facilitated by their class and ethnic positionings.