The new UN recommendations for the phased development of national Systems of International Tourism Statistics are presented, with the principal definitions and classifications. Some problems in collecting, analysing and interpreting tourism data are discussed. The principal tourism statistics are presented for the 39 countries of the European region for 1975 with estimates of international tourist arrivals and tourist-inights according to UN definitions. Tourism is highly seasonal and subject to strong fluctuations in trends and also to changes in seasonal patterns. Time series analysis enables the use of seasonally-adjusted data for historic and current monitoring of tourism flows and for forecasting. Some recommendations are proposed for furthering tourism statistics.