Study data were gathered from the Blue Book and include only cases involving 'pure' restraints of trade. Data analysis reveals that more individuals served time in jail for Sherman Act violations during the study period than in the years from 1890 to 1960 combined. Of 431 individuals who were subject to sentence for Sherman Act violations in the 1970's, 405 (or 94 percent) ultimately served some sentence. Further, the sentencing performance of the courts in the last 4 years of the 1970's was outstanding in that 99.6 percent of persons subject to sentence in misdemeanor and felony cases served some sentence. Besides incarcerating more offenders, the courts imposed stricter fines against both corporate and individual offenders. The average fine imposed against Sherman Act offenders increased substantially during the 1970's: from 1971 through 1976, the average fine was $8,400 and from 1976 through 1979, the average fine was $17,500. In addition, the percentage of judges imposing jail sentences against Sherman Act offenders also increased during the 1970's. From 1971 through 1975, judges imposed at least one jail sentence in one of every five Sherman Act cases (20.5 percent). However, in misdemeanor and felonly cases processed from 1976 through 1979, at least one offender was sentenced to jail in one of every three Sherman Act cases (32.6 percent). The passage of the Antitrust Procedures and Penalties Act may have contributed to stricter antitrust sentencing. Although the deterrent impact of such sentencing is still not clear, the trend of stricter sentencing in Sherman Act cases promises to continue. Tabular data and footnotes with references are included.