The development of male infertility is increasing rapidly worldwide with numerous causative agents and idiopathic causes. Infertility conundrum coincides with the epidemic of abnormal body weight which holds sway to countless pathological conditions. This study was therefore designed to evaluate the relationship between low body mass index (BMI), sperm counts and seminal electrolyte concentrations in young adults. A total of one hundred (100) students of the Niger Delta University constituted the study subjects. The age bracket was pegged between 18-35 years. The study was stratified into two categories; normal BMI (20-25) and underweight (< 19). The BMI, electrolytes and sperm concentrations were analyzed using WHO approved standards and procedures. Data generated from the mathematical and empirical analysis were analysed using student t-test and Pearson correlation obtained using SPPS version 18-20 packages. The result showed a significant decrease (p<0.05) in seminal sodium and bicarbonate in the underweight when compared to normal BMI, whereas seminal potassium was on the contrary. Correlation between BMI and sperm count revealed non-significant relationship with Pearson coefficient (r) = - 0.077; p – value = 0.778. In conclusion, the distorted electrolytes observed in the study are a plausible predisposition of underweight to infertility.