This paper explores how multidisciplinary teams (MDTs) balance encoded knowledge, in the form of standardised outcome measurement, with tacit knowledge, in the form of intuitive judgement, clinical experience and expertise, in the process of clinical decision making. The paper is based on findings from a qualitative case study of a multidisciplinary in-patient neurorehabilitation team in one UK NHS trust who routinely collected standardised outcome measures. Data were collected using non-participant observation of 16 MDT meetings and semi-structured interviews with 11 practitioners representing different professional groups. Our analysis suggests that clinicians drew on tacit knowledge to supplement, adjust or dismiss 'the scores' in making judgements about a patients' likely progress in rehabilitation, their change (or lack of) during therapy and their need for support on discharge. In many cases, the scores accorded with clinicians' tacit knowledge of the patient, and were used to reinforce this opinion, rather than determine it. In other cases, the scores, in particular the Barthel Index, provided a partial picture of the patient and in these circumstances, clinicians employed tacit knowledge to fill in the gaps. In some cases, the scores and tacit knowledge diverged and clinicians preferred to rely on their clinical experience and intuition and adjusted or downplayed the accuracy of the scores. We conclude that there are limits to the advantages of quantifying and standardising assessments of health within routine clinical practice and that standardised outcome measures can support, rather than determine clinical judgement. Tacit knowledge is essential to produce and interpret this form of encoded knowledge and to balance its significance against other information about the patient in making decisions about patient care.