Quantitation methods in clinical pathology have to be normalized and standardized both from the instrumental and the methodological point of view to guarantee a defined level of precision and accuracy independent of the site where they are applied. The comparability of results obtained in different laboratories is the basis for the application of standardized diagnostic classification systems and therapeutic schemes. Remote quantitation based on standardized evaluation tools could be a way to reach the goals mentioned above. Diagnostic DNA image cytometry, increasingly used as a routine method in clinical pathology, will serve as an example for demonstrating the feasibility and usefulness of a concept of remote quantitation. We report a system for a remote DNA ploidy analysis, based on client server technology, and accessible via Internet or ISDN connections (Quantitation Server EUROQUANT). This system (i) allows the cytometric measurement of the DNA content of cells for diagnostic purposes, (ii) provides the user with comprehensive quality control of such measurements, (iii) helps in trouble-shooting, and (iv) gives assistance in diagnostic interpretation. The system uses the principles of telepathology and Internet technology. To date, more than 40 laboratories from Europe, USA, and Asia have successfully performed analyses on about 3,000 ploidy data sets.