Treatment for individuals convicted of sex offenses has substantially improved in developed countries in recent decades, providing practitioners with an extensive literature to guide the implementation of effective programs to reduce sexual reoffending. Nevertheless, sexual offending rehabilitation is still in its infancy in Latin American countries such as Uruguay, so little is known about the transference and implementation of evidence-based programs. The current study examines the strengths, barriers, and challenges of implementing a sex offenses treatment program in Uruguay. The findings suggest some achievements of the program, but also several problems with implementation. Some problems are universal among different countries (e.g., scarce resources and facilities, insufficiently trained staff, and unexpected changes in the organization), but others were particularly relevant in the Uruguayan context (e.g., government policy alien to a rehabilitation approach, lack of appropriate prison facilities, lack of training for therapists from a cognitive-behavioral perspective). All these difficulties must be anticipated and solved for successful generalizability of rehabilitation programs to different correctional systems.