Noninvasive functional brain stimulation techniques such as transcranial magnetic stimulation (tms) offer the unique possibility of directly interfering with local and remote neural network activity in conscious human participants, with a quantifiable impact on behavior or cognition. This makes brain stimulation in many ways complementary to brain imaging and a combination of both techniques particularly desirable. Brain stimulation can be combined with brain imaging either in two separate experimental sessions or also simultaneously by using tms inside the mr scanner. The simultaneous combination of tms with fmri enables the stimulation of brain circuits while concurrently assessing direct and remote neural network effects across the entire brain and linking these network activity changes to the induced behavioral manipulation. This chapter introduces the workings of tms and its application in fundamental brain research, rehabilitation, and psychiatry and describes the different possibilities and methodological challenges of combining brain stimulation and brain imaging. Concrete research studies are used to exemplify how valuable such combined brain stimulation and brain imaging studies can be for fundamental and clinical brain research.