The study aimed at elucidating the extent to which Chemistry education students in the universities based in Rivers State had displayed mastery for the use of conventional nomenclature and standard units in the learning of organic, inorganic and physical Chemistry. The design was a cross-sectional survey. The sample of 115 students composed of, students from Rivers State University, University of Port Harcourt and Ignatius Ajuru University of Education obtained through stratified random sampling technique were tested with 30 test items (code named TUNIC) that was well validated and had reliability coefficient of 0.96 via Pearson Product Moment Correlation Technique. The relevant data gathered were subjected to mean, standard deviation, t-test and ANOVA. The results of the study showed that, the three universities exhibited poor mastery of conventional nomenclature in inorganic and organic Chemistry, moderate mastery of conventional units in physical Chemistry. Rivers State University and University of Port Harcourt exhibited moderate mastery in the use of conventional nomenclature and units in Chemistry while Ignatius Ajuru University of Education exhibited poor mastery in the use of conventional nomenclature in Chemistry. University type and gender were not significant factors influencing undergraduate Chemistry education students’ mastery and use of conventional nomenclature in Chemistry.