To increase the likelihood that probationers with serious mental disorders can be identified by probation agencies, we tested the utility of two promising mental health screening tools, the K6 and the Brief Jail Mental Health Screen (BJMHS), in identifying probationers with DSM-IV Axis I mental disorders. In this study, 4,670 probationers completed the screening tools as part of routine intake procedures at a probation agency. We interviewed a subset of 149 probationers using a structured clinical interview to determine whether they met the criteria for an Axis I anxiety, mood, or psychotic disorder at any point during their lifetimes. The BJMHS correctly identified 77% of probationers with mental disorders overall, and contrary to our hypotheses, the measure was as sensitive with women as it was with men. Adding items assessing post-traumatic stress disorder provided some incremental utility to the measure. The K6 demonstrated similar levels of sensitivity to the BJMHS when using a lower cutoff score informed by prior research with offenders. Contrary to prior research, we found that the BJMHS was sensitive to mental disorders among female probationers. We suggest that probation agencies implement either the BJMHS or the K6 as part of their intake procedures to identify probationers with serious mental disorders so the complex needs of this group can be better addressed.