The ability to quantify improvements in care in response to practice improvement initiatives is dependent on an effective measurement instrument. We sought to develop and test the Quality in Intensive Care Patient Care Scale (QICPaCS) that was formed through the combination of the Quality Patient Care Scale, the Australian College of Critical Care Nurses Competency Standards and the Critical Care Family Needs Inventory. This two-phase study assessed the content validity, inter-rater reliability and construct validity of the QICPaCS in an Australian Intensive Care Unit (ICU). An expert panel of nine critical care nurses assessed content validity by rating each domain and item for relevance, clarity and representativeness. Three experienced critical care nurses observed 100 episodes of care in a tertiary referral ICU. Inter-rater reliability was assessed through dual measurement of 20 episodes of care. Construct validity was assessed using exploratory factor analysis, with alpha reliabilities determined for each factor. Content validity was rated high with an average agreement of 97% for relevance, 97% for clarity and 94% for representativeness. Inter-rater reliability was high (kappa 0.82). A three factor model incorporating ten items explained >60% of the variance in quality of care provided. Factors included informed nursing care, moral and ethical care and communication. The content validity and inter-rater reliability of the QICPaCS were demonstrated to be high in this study. Although this exploratory model is parsimonious, given that only ten items contributed to measurement of quality of care, further investigation to identify more complete description of the construct is necessary.