Research suggests that psychological factors are related to persistence in science, especially for underrepresented students; however, most psychological instruments have been validated through studies conducted at predominately White institutions. In the current study, we report reliability estimates for measures of science identity, science motivation, and science self-efficacy with a sample of undergraduate college students from a Hispanic Serving Institution (N = 309). Internal consistency and test-retest reliability were estimated with Cronbach's alpha and intra-class correlation coefficients, respectively. We report Cronbach's alpha values separately for male (N = 152), female (N = 152), Hispanic (N = 111), and White (N = 115) students. We also examined whether there were statistically significant differences in the Cronbach's alpha values between these groups. The results demonstrated good to excellent reliability estimates for internal consistency ([alpha] ranged from 0.89 to 0.96) and test-retest reliability (ICC ranged from 0.76 to 0.80) for all groups. There were no significant differences in Cronbach's alpha values between students identifying as male versus female or between Hispanic and White identifying students. We conclude by urging science education researchers to examine, report, and interpret reliability estimates for their measures for each dataset.