Several studies in the United States and Canada have shown that differences in arrest rates for males and females are diminishing and that the property theft rate for females has risen sharply. Various theories attributing this trend to changing sex roles and increased female participation in the labor force are reviewed. This study sought to test the hypothesis that as more women occupy roles outside their family and are less tied to traditional social roles, female crime will reflect a corresponding increase. The time period 1931 through 1968 was selected for analysis, and the crime rate was measured by the female conviction rate for indictable offenses because of variations in police reporting methods prior to 1962. The following independent variables were selected as indicative of women's structural position in society: the total fertility rate, the female labor force participation rate, and the numbers of females granted postsecondary degrees. Parallel measures of male crime rates were included as independent variables. The female conviction rates rose steadily until an all-time high in 1940, remained quite high until 1944, and then declined to a low point in 1956. From 1957 to 1968, the rates increased in all but two years and approached the highs of the 1937-43 period. The highest rates for theft alone, however, have occurred in recent years. Statistical analysis of the variables generally confirmed the hypothesis. Findings for the female theft conviction rate were more consistent than for overall conviction rates. Increased female participation in nonviolent property offenses can be attributed to both the pressures and increased opportunities for crime that develop when women are more involved in extrafamilial roles. It is possible that variations in female crime rates can be explained by the changing responses of police and judges and bear little relationship to actual criminal activities. Tables and a bibliography containing 25 references are included.