The role of intellectual ability and motivation, as well as the conscientiousness personality trait in predicting academic achievement, has been widely demonstrated in a large body of research earlier (e.g. Harris, 1940; see also Ziegler, Danay, Schölmerich & Bühner, 2010). The purpose of this article is to study the relationship between these variables and academic success. Consistent with the literature presented in the introduction, statistical evidence suggests that intellectual ability is positively associated with academic achievement (e.g. Dweck, 1986; Elshout and Veenman, 1992; Harris, 1940). Although the association was relatively weak, the first hypothesis was supported. An implication of this is that for low intelligence students, teachersThus, the second hypothesis was supported by the results. This correlation also replicates previous research suggesting that personality traits are more important predictors of academic achievement than simple intelligence (e.g. Fonteyne, Duyck & De Fruyt, 2017; and Stadler, Aust, Becker, Niepel & Greiff, 2016 ). The reason this may have happened is that individuals who have a conscientious personality type, who persist in the learning process at university levels, play a more important role than intelligence alone. If an individual has worked hard to understand and apply the concepts and has completed a high volume of effective academic study for their assessments, they are more likely to succeed (Furnham, Chamorro-Premuzic, & McDougall, 2003; Spengler, Lüdtke, Martin and Brunner). , 2013). An implication of these findings for teachers regarding their students is the need to develop methods that increase conscientiousness, that is, the introduction of time management and organization. Therefore, there is not enough evidence to support the third hypothesis. This may be due to the small sample size and non-representativeness. The results of the study could have been more significant if the sample size had been larger. In turn, the sample of students was taken from only one university in a single state, which means that the results obtained cannot be generalized to all first-year psychology students as population. If the study had taken a sample of psychology students from various Australian universities, this would increase its representativeness. As a result, the study can be criticized for its reduced reliability and external validity.