The present article focuses on the conce pt of achievement motive which currently presents certain difficulties to investigators due to a lack of consensus on its meaning. Two investigations were undertaken with 447 undergraduate students (237 male, 210 female): (1) to develop a scale for measuring achievement motive in terms of Social Need Achievement (SA) and Personal Need Achievement (PA) and (2) to clarify the relationships between personal traits related to achievement motive. Results indicated that: (1) Challenge Success Need (CSN) should be incorporated into the co ncept of achievement motive: (2) SA has little relation to personal traits while PA is related to self-actualization, and CSN being possibly related to toughness and vitality ; and (3) there are differences between males and females concerning achievement motive. The results, in general, proved the need for a multi-faced definition of achievement motive.