A study was conducted to estimate repeatability, minimum number of evaluations to which a trait should be subjected, and the inter-relationship of 19 traits related to bunch and fruit in Bang Boet dura oil palms. Repeatability values were found varying between 0.098 – 0.691. The optimum number of bunches for observation of bunch weight, fruit weight per bunch, stalk weight per bunch, number of fruits per bunch, weight of large size fruits, and number of large size fruits were three to six bunches, while the number to assess weight of small size fruits, weight of medium size fruits, number of medium size fruits and number of small size fruits were 7-11 bunches. The number of bunches for determing percentage of crude palm oil and palm kernel oil per bunch should be four and eight bunches, respectively, whereas the optimum number of fruits for observation of kernel thickness, fruit width, fruit length, weight per fruit, percentages of mesocarp, shell and kernel were four to nine fruits, and for endocarp and mesocarp thickness were 18- 22 fruits. High positive correlations were observed between bunch weight and fruit weight per bunch, bunch weight and stalk weight per bunch, fruit weight per bunch and weight of large size fruits, bunch weight and weight of large size fruits, and fruit weight per bunch and number of large size fruits, with the values of 0.98, 0.92, 0.91, 0.88 and 0.88, respectively. Path coefficient analysis showed that oil palm yield was directly influenced by bunch weight and number of bunches per plant. Oil palm bunch weight was determined mainly by fruit weight per bunch, which was directly affected by weight of large size fruits. High percentage of mesocarp per fruit influenced the percentage of oil per bunch. Oil palm breeders can apply this information to select for high yield through these yield components.