Implementation of a Quality Assurance (QA) program in geological investigation is very significant and essential, especially when the investigation is carried out for selection and evaluation of strategic and vital project sites. The current work is a case study for selection and evaluation of a strategic site in Iraq where a QA program was implemented for the first time in the Iraq Geological Survey (as a Contractor) as a mandatory condition implied by the Client for all work carried out and included in the geological investigation. The geological investigation included six main activities: 1) geology, 2) hydrogeology, 3) geophysics, 4) engineering geology, 5) drilling and 6) laboratory work. The main roles of QA staff were to: 1) check the qualifications of all staff members involved in the six activities, 2) verify work procedures by means of which the staff members of each activity were performing their tasks, 3) follow-up all carried out works in the field, laboratory and office, 4) verify all types of work outputs by the staff members of the six activities, and 5) recognize any nonconformance in any type of carried out work before been recognized by the QA and/ or Quality Control (QC) staff of the Client. During the performance of the contract that lasted for 30 months, three nonconformance cases by the Contractor were recognized by the QA staff members and relevant corrective actions were performed. The three cases were not detected or recognized by the QA and QC staff members of the Client.