Estimating phosphorus intake in grazing sheep is difficult since hand-picked samples of forage do not represent actual intake. Results showed that faecal P did reflect dietary P levels. A minimum of 30 sheep should be sampled to obtain an error of 6% for pooled analysis of faecal P. The relationship between the level of P in feed and that in faeces was remarkably constant. Bone P levels tended to follow bone Ca levels rather than dietary P levels.