OBJECTIVES: To map levels of the Health Status Classification System – Preschool (HSCS-PS) into the Health Utilities (HUI) Mark 2 (HUI2) and Mark 3 (HUI3) measurement systems. This will create a generic utility-based measure of health-related quality of life (HRQL) applicable to all persons 2.5 years of age and older.  METHODS: The existing HSCS-PS is based on the HUI2 and HUI3 (HUI2/3) classification systems. The attribute levels of the HSCS-PS were mapped into the HUI classification systems attribute levels and, by extension, to the existing HUI scoring functions for calculating HRQL utility scores. A questionnaire was developed asking participants to map level descriptions between matched HSCS-PS and HUI2/3 attributes.  Mapping questionnaires were completed by 14 health care professionals (6 nurses and 8 physicians) responsible for the care of pre-school aged children diagnosed with cancer or developmental problems. Percent exact agreement was calculated among participants for each set of HSCS-PS level mappings. Differences in proportions of level mappings within each HSCS-PS attribute were tested using Fisher’s exact test. Strength of agreement was described as follows: "exact wording assignment" or  >70.0 % “very strong”; 50.0 to 69.9 % “strong”, 40.0 to 49.9 % “moderate”.  RESULTS: A total of 41 levels from 10 attributes of the HSCS-PS were mapped to 19 levels in 5 HUI2 attributes and 33 levels in 8 HUI3 attributes (total=52).  Differences in mapping proportions were significant (p<0.001) for all 12 sets of levels.  Agreement was very strong for 86.5 % (n=45), strong for 11.5 % (n=6), and moderate for the remaining 2.0% (n=1) of the mappings.  CONCLUSIONS: There was strong to very strong agreement among health care professionals about the overwhelming majority of the mappings of HSCS-PS to HUI2/3 attribute levels. Future work will repeat the mapping exercise with parents of preschool children in general and clinical populations, and include validation studies.