In this chapter, the authors make the case for the importance of partnerships for science education reform. Building and nurturing appropriate partners for tasks large and small helps to overcome formidable barriers. Good partnerships can shorten the time from planning to implementation and help ensure that reforms are sustained long enough to have the anticipated impact. But partnerships are complex and fragile. To create and sustain them requires expending valuable resources—time, energy, and money—careful planning, and continuous evaluation, feedback, and nurturing (Kingsley and O’Neil 2004). To illustrate their main points, the authors will use the National Science Foundation- (NSF) funded Mathematics and Science Partnership (MSP) program that they direct as a source of examples.