Studies were made in August 1978 on the N-balance and hematological characteristics of 18 men living in the village of Kalugaluvi (altitude: 1,500m) near Lufa, which is 60km from Goroka, in the Eastern Highland Province of Papua New Guinea. The average daily protein intake on 3 consecutive days was 95.2 +/- 29.3 mgN/kg (35.2 +/- 10.7 g protein/day), and 32.6 +/- 18.7% of the total protein intake was in the form of animal proteins. The calculated nutritional value of the dietary protein, scored according to the 1973 FAO/WHO pattern, was 83.7 +/- 10.6. Urinary and fecal N excretions during the same period were 81.9 +/- 18.7 and 26.3 +/- 11.8 mgN/kg, respectively, giving a nitrogen balance of -13.5 +/- 24.9 mgN/kg. From N-balance data on individuals, the N-intake for maintenance of a zero N-balance was estimated as 116.3 +/- 48.6 mgN/kg (mean 95% confidence interval). Hematological data showed normal or rather high values for hemoglobin (16.90 +/- 1.05 g/100 ml) and serum proteins (8.05 +/- 0.40 g/100 ml). The increased level of serum proteins was associated with an increased globulin level.