Outsourcing is rapidly growing in the pharmaceutical industry. When the manufacturing activities are outsourced, control of the product's quality has to be maintained. One way to confirm contract manufacturer's GMP (Good Manufacturing Practice) compliance is auditing. Audits can be supported for instance by using GMP questionnaires. The objective of this study was to develop a tool for the audit preparation of pharmaceutical contract manufacturers and to validate its contents by using Delphi method. At this phase of the study the tool was developed for non-sterile finished product contract manufacturers. A modified Delphi method was used with expert panel consisting of 14 experts from pharmaceutical industry, authorities and university. The content validity of the developed tool was assessed by a Delphi questionnaire round. The response rate in Delphi questionnaire round was 86%. The tool consisted of 103 quality items, from which 90 (87%) achieved the pre-defined agreement rate level (≥75%). Thirteen quality items which did not achieve the pre-defined agreement rate were excluded from the tool. The expert panel suggested only minor changes to the tool. The results show that the content validity of the developed audit preparation tool was good.