Efficient use of limited resources is among the objectives of efficient management and employing modern techniques of management is very effective in this field. Communications management is quite important in project-oriented organizations. PMBOK guideline is a good guideline to create efficient and effective communication. In this paper the application of communication management field of PMBOK guideline has been presented in projects processes of a project-oriented organization for effective communications management. To better understand the concepts, processes associated with projects in Lorestan province Gas Company have been employed as a project organization. The methodology includes three steps of data collection through interviews with relevant personnel, identification of processes and processes analysis based on Communications Management field of PMBOK guideline. Additional and unnecessary information turnover in the processes has been identified and removed. The results showed that creating correct communication in an organization will eliminate many of the existing delays in the processes. Also the results showed that communications management improvement leads to the improvement in all knowledge fields of PMBOK guideline in an organization, resultinginreducedtime andcost, efficient use oflimited resourcesand increased efficiencyand viabilityofthe organization.