The Canadian Institute for Health Information (CIHI) provides accurate health information needed to establish sound health care policies. The CIHI mandate is to develop and co-ordinate a uniform approach to health care information in Canada. The institute uses the International Classification of Diseases (ICD) system to record the most responsible diagnosis for each hospital admission. This investigation was conducted to determine if six ICD protein-calorie malnutrition (PCM) codes could be used for health care utilization analyses. Aggregate data (1996 to 2000) from the CIHI discharge abstract database were used. The data analyzed were the most responsible diagnoses data for the six PCM codes and a single summary statistic for all other "non-malnutrition" diagnoses for all long-term care facility residents aged 65 or older who were transferred to an acute care facility. In this population, fewer than five hospital admissions per year were assigned a PCM code. There were too few PCM cases to do trend analyses for morbidity or mortality. This study suggests a lack of recognition and documentation of PCM as a specific health condition in older adults. Lack of tracking of this diagnosis prevents documentation that could lead to policy changes to support older adults' nutrition.