This chapter describes an agent-based model called SimDrugPolicing that explores the relative impact of three law enforcement strategies-standard patrol, hotspot policing, and problem-oriented policing-on an archetypal street-based illicit drug market. Using data from Melbourne (Australia), we simulate the relative effectiveness of these different drug law enforcement approaches. We examine the complex interactions between users, dealers, wholesalers, outreach workers and police to examine the relative effectiveness of the three drug law enforcement strategies, analyzing several outcome indicators such as the number of committed crimes, dealers 'and users 'cash, overdoses and fatal overdoses. Our results show that problem-oriented policing is the most effective approach to disrupting street level drug markets in a simulated urban environment.