SUMMARY1. A general description is given of Loliondo Controlled Area which sets out the reasons for this census and the conditions that determined the manner in which it was conducted. The major features of the vegetation and fauna are outlined.2. The census was primarily a stratified sample count, and the types of stratification and sampling are described.3. Some areas were total‐counted using a series of adjacent counting blocks.4. In a few instances large groups of animals were estimated rather than counted, but aerial photographs were taken to allow an estimate of bias to be made.5. A number of practical considerations did not allow the census to follow the original plan in every detail.6. The results are set out in Tables 3 and 4, and Figure 4. They show considerable, and rather variable, bias in estimations of numbers in large groups of animals. The estimates of numbers from sample counts for most species show wide confidence limits, but agree satisfactorily in such cases where a comparison can be made with the estimates from total counts. It is thought that a more efficient stratification, and a larger number of samples, will reduce the standard error of such estimates, to give more acceptable fiducial limits.7. The census of 6,734 km2occupied a pilot and observer for 10 d during which 41 h were flown in a Cessna 185 aircraft. The total cost was E. A. Sh.13,400.8. The method is discussed, and proposals put forward for increasing the accuracy of sample counts.9. The implications of the census results in the construction of sustained yield equations are considered.10. Some ecological points emerging from the