Three studies were conducted in an initial attempt to investigate the psychological importance of trivial everyday frustrations encountered by preschool children. Study 1 analyzed the frequency and quality of experiences that could be interpreted as interfering in some way with children's natural pursuit of their desires. In a nursery school setting, 97 3- and 4-year-olds were observed over several days for a total of 30 minutes. Anecdotal records were kept by observers, which were later classified into eight categories of frustrating experiences. Analysis of results indicated that such experiences were surprisingly frequent (approximately one per five minutes). Study 2 investigated whether the results were peculiar to the school environment. Thirty-minute consecutive observations of four-year-olds were conducted on public playgrounds and beaches. The data was unexpectedly consistent with the first study. The third study was designed to analyze the wide range of experiences for different children. The original procedure was repeated with the original subjects during the next school year. The relative frequency of constraining events was stable, indicating that certain children are more prone than others to such occurrences. Discussion focuses on theoretical and practical issues raised by the research, including adequacy of methodology, significance of the events in determining behavior patterns, and whether it is wise for adults to intervene to reduce frequency of frustrating interactions. (DP)