The objective of this research is 1) to study the level of competency factors, organizational citizenship behavior factors, organizational commitment factors and operational efficiency of company employees, oil pipeline equipment sales business in bangkok 2) to study the factors affecting operational efficiency of company employees, oil pipeline equipment sales business in bangkok. The quantitative research method was used by questionnaires. The sample population consisted of 190 employees of oil pipeline equipment sales business, calculated according to the formula using G * Power 3 program by using frequency, percentage, mean, standard deviation statistics and multiple stepwise regression analysis method. The results of the study found that 1) the overall operational efficiency level was the highest and the level of factors affecting operational efficiency were at the highest level, namely competency, organizational citizenship behavioral and organizational commitment factors respectively 2) Factors affecting operational efficiency were organizational membership behavior (X₂), organizational commitment (X₃) and competency (X₁). These factors could predict a combined operational efficiency of 72.20 percent which can be presented as an equation as follows: Ŷ_tot = 0.450 + 0.220 (X₂) + 0.337 (X₃) + 0.353 (X₁).