The study examined the place of genotype, blood group and socio-economic-status on students’ academic achievement in sciences in tertiary institution in Rivers State. Over the years the factors responsible for the improvement or poor academic achievement of students in school science has been studied in some details, however, available research records showed that the only factor or area where the study has not been fully done is the role or contribution of heredity to students’ academic achievement. This study which juxtaposed the place of students genotype, blood groups and the SES with their academic achievement adopted an Ex-post facto survey design where the genotype and history of students were collected from the students medical records as the way the medical records reported about the students, while the Cumulative Grade Point Average (CGPA) were also collected from the senate approved semester results of the students. The study was guided with four research question and a corresponding four null hypotheses. The population of the study was restricted to only year one students because of the medical history. The result of the findings include,1. Sex and genotype have a strong relationship 2.genotype of the learner determines to a large extent the abilities and achievement of students in the sciences courses 3. That as well, the blood group of the individual compliments the genotype as well as the achievement of students in sciences. However, the SES of students never influenced the outcome of students.