The development of a 14-item screening instrument designed to identify life-style criminality is discussed. This instrument, which is divided into four primary sections (irresponsibility, self-indulgence, interpersonal intrusiveness, and social rule breaking), is scored on the basis of information commonly found in an individual's presentence investigation report. Cutting scores were derived using a sample of 516 inmates confined in a maximum security federal penitentiary. The instrument was then validated by contrasting a group of 25 penitentiary inmates (hypothesized to contain a large percentage of life-style criminals) with a group of 25 prison camp inmates (hypothesized to contain few life-style criminals). Large differences were noted between these two groups on all four sections, regardless of whether assessed by sections or as a global measure. Even after removing items which may have been considered in originally assigning subjects to a camp or penitentiary, large group differences remained.