Fragmented and complex nature of contemporary public policy problems require governments to change their traditional public administration approaches and force public administrators to provide involvement of all actors such as private firms, non-profit organizations, and citizens in policy making and implementation. In this diverse policy environment, using governance tools such as contracting out some public services, building networks, and establishing citizen participation mechanisms are considered as essential components of this new approach. Public administrators should not act as the only problem solver, but they should be facilitators in collaborative problem solving to mobilize the other actors. Along with the benefits of using these tools, there are some challenges for public administrators. Considering these difficulties, appropriate use of these tools provides public administrators to effectively address contemporary complex problems such as terrorism, drug abuse, emergency management, and healthcare crisis.