When a youth is accused of committing a crime, juvenile justice system arbiters, such as probation officers, interview both the youth and the youth’s guardian to gather information before deciding to either process the youth formally or informally. Factors about a youth that are unrelated to the criminal charge may contribute to arbiters’ processing decisions. Such extralegal factors include demographic characteristics and characteristics of the youth’s context (e.g., home environment, peer delinquency). Little is known about how extralegal factors other than age and race affect youth processing. The present study draws on data from probation officer assessment interviews with 359 male, first-time, low-level juvenile offenders, as well as longitudinal self-report and official records of a youth’s reoffending after his first arrest, to determine how extralegal factors affect probation processing decisions, and whether processing is associated with youth reoffending and rearrest. The results indicate that even after taking into account legal factors and demographic characteristics, youth are more likely to be processed formally if they refuse to comment on the charge, if their probation officers believe their guardians to be relatively more disapproving of their friends, and if their probation officers perceive their home environments to be more problematic. Although youth who are processed formally self-report reoffending at the same rate as youth who are processed informally, youth who are processed formally are more likely to be rearrested in the subsequent 6 months. Implications for how processing decisions may promote sustained involvement in the juvenile justice system are discussed.