To be accurate and equivalent, laboratory results should be traceable to higher-order references. Furthermore, their quality should fulfill acceptable measurement uncertainty as defined to fit the intended clinical use. With this aim, in vitro diagnostics (IVD) manufacturers should define a calibration hierarchy to assign traceable values to their system calibrators and to fulfill during this process uncertainty limits for calibrators, which should represent a proportion of the uncertainty budget allowed for clinical laboratory results. It is therefore important that, on one hand, the laboratory profession clearly defines the clinically acceptable uncertainty for relevant tests and, on the other hand, endusers may know and verify how manufacturers have implemented the traceability of their calibrators and estimated the corresponding uncertainty. Important tools for IVD traceability surveillance are quality control programmes through the daily verification by clinical laboratories that control materials of analytical systems are in the manufacturer’s declared validation range Internal Quality Control (IQC) component I and the organization of Exter nal Quality Assessment Schemes meeting metrological criteria. In a separate way, clinical laboratories should also monitor the reliability of employed commercial systems through the IQC component II, devoted to estimation of the measurement uncertainty due to random effects, which includes analytical system imprecision together with individual laboratory performance in terms of variability. Da bi bili tacni i ekvivalentni, laboratorijski rezultati treba da budu sledljivi do referenci viseg reda. Stavise, njihov kvalitet treba da ispostuje prihvatljivu mernu nesigurnost definisanu tako da odgovara planiranoj klinickoj upotrebi. Sa ovim ciIjem, proizvodaci in vitro dijagnostickih sredstava treba da definisu hijerarhiju kalibracije kako bi dodelili sledljive vrednosti kalibratorima svojih sistema i kako bi u toku ovog procesa ispostovali granice nesigurnosti za kalibratore, sto bi trebalo da predstavlja srazmeran deo budzeta za nesigurnost odobrenog za rezultate klinicke laboratorije. Stoga je vazno da, s jedne strane, laboratorijski strucnjaci jasno definisu klinicki prihvatljivu nesigurnost za relevantne testove, a da, s druge strane, krajnji korisnici mogu da znaju i verifikuju na koji su nacin proizvodaci implementirali sledljivost svojih kali- bratora i procenili odgovarajucu nesigurnost. Vazne alatk|e za nadzor sledljivosti in vitro dijagnostickih sredstava su progra- mi za kontrolu kvaliteta putem dnevne verifikacije od strane klinickih laboratorija da su kontrolni materijali analitickih sis­tema u okviru validacionog opsega koji je deklarisao proizvodac (I komponenta programa Internal Quality Control, IQC) i organizacija sema za eksternu procenu kvaliteta (External Quality Assessment Schemes) koje ispunjavaju metroloske kriterijume. Klinicke laboratorije takode treba zasebno da prate pouzdanost primenjenih komercijalnih sis­tema kroz II komponentu programa IQC, posvecenu proceni merne nesigurnosti usled nasumicnih efekata, koja obuhva- ta nepreciznost analitickih sistema kao i performanse pojedinacnih laboratorija u pogledu varijabilnosti