In-house hematology testing has distinct advantages and requires an ongoing commitment to quality assurance. Hematology POCA should always be operated by qualified personnel who have received adequate instrument operational, safety, and biohazard training. Likewise, blood samples should be acquired and handled, and blood smears made, by adequately trained personnel. Nonstatistical QA procedures are vital to minimize all types of laboratory error (preanalytical, analytical, and postanalytical) and include many common sense procedures already performed in well-maintained veterinary practices. Blood smear review is a critical component of QA in hematology testing. Each veterinary practice using POCA must determine frequency of QC (ie, frequency of “running controls”) based on factors such as POCA analyzer type, clinic operating budget, and caseload; at least daily QC is encouraged if possible. QC should be performed frequently enough that QCM are used cost-effectively and that POCA analytical error can be reliably detected. Unacceptable QC data (however defined) should prompt investigation of the POCA, reagents, and operator. Veterinarians and veterinary technicians are encouraged to pursue continuing education about laboratory quality management and to utilize relevant guidelines, such as those available from the ASVCP.