The purpose of the study was to determine whether North Carolina's 1994 Structured Sentencing Act (SSA), which eliminated parole eligibility and time off for good behavior, was resulting in notably high levels of problematic behavior of inmates sentenced under that law. To have a ratio-scale measurement of the seriousness of each of 43 disciplinary offenses, the study surveyed 88 North Carolina prison superintendents and 27 higher level administrators. The 88 responding participants rated the seriousness of the 43 offenses on a 50-point Seriousness scale. Because the natural experimental design allowed causal analysis, the Cox regression risk ratios and binomial regression exponentiated coefficients presented differences that can, to a substantial extent, be attributed to implementation of structured sentencing and not just to differences in the types of people incarcerated under fair sentencing and structured sentencing. Findings showed that inmate disciplinary enforcement activity increased substantially in the Division of Prisons since the implementation of the SSA. Interviewed prison workers generally agreed that SSA inmates were more difficult to control and commit more disciplinary infractions than other inmates. Some implications of these findings are discussed. 2 tables and 28 references