The ISPE Good Practice Guide on Sampling for Pharmaceutical Water, Steam, and Process Gases was created for users of water, steam, compressed air or process gases and impacts facilities, production, and quality control personnel within a facility. This Good Practice Guide applies to manufacturers of pharmaceuticals, medical devices, biologics, cosmetics, and related products as well as equipment manufacturers, vendors, and other industries outside of the pharmaceutical arena. The intent of sampling is to take a small but representative portion of a much larger stream where the sample collected accurately represents the content of the larger stream. The sample collected should not be altered or changed in any way because of the sampling process, but this is an impossibly difficult proposition, as all sampled utilities come into contact with air, containers, etc., during the sampling process. Effective sampling is of paramount importance to the success of any pharmaceutical critical utility system. Extracting a representative sample from a utility system can be an involved and complicated process and error may be introduced. Improper sampling may have a negative impact on company image, cost, productivity, ethics, and regulatory liability. The ISPE Good Practice Guide on Sampling for Pharmaceutical Water, Steam, and Process Gases covers the critical utilities of pharmaceutical water, pharmaceutical steam, and pharmaceutical process gases. Guidance is provided on aspects of sampling from valve design, the number, location, and placement of sample valves, sampling technique, frequency, and sample storage including delivery to the testing laboratory. It has been assembled to provide assistance to designer engineers, process engineers, facilities engineers, quality assurance staff, quality control staff, production staff and any other group, team, or individual that may be impacted by the results of a sampling program. The ISPE Good Practice Guide on Sampling for Pharmaceutical Water, Steam, and Process Gases aims to establish good manufacturing practices for sampling to minimize sample contamination from human contact, error, atmospheric, or environmental conditions which could alter laboratory results, and provide inaccurate data. The scope of this Good Practice Guide stops when the sample is delivered to the laboratory for analysis. Goals of the ISPE Good Practice Guide on Sampling for Pharmaceutical Water, Steam, and Process Gases To provide the pharmaceutical industry with standards and best practices for sampling in a comprehensive single reference To help minimize sampling errors and their contribution to out of specification results, which can cause costly work and production stoppages, investigations, and disruptions in manufacturing, Quality Control/Quality Assurance, and engineering organizations The ISPE Good Practice Guide on Sampling for Pharmaceutical Water, Steam, and Process Gases is of benefit to laboratory, Quality Control/Quality Assurance, engineering, facilities, and operations personnel.