A wide variety of infectious diseases may afflict the central nervous system (CNS). Magnetic resonance imaging (MRI) is exquisitely sensitive in the detection and localization of such lesions. Moreover, many CNS infections exhibit signatures on MRI that make imaging quite specific. Diffusion-weighted imaging, for example, is of great value in differentiating bacterial from other CNS infections. Likewise, accquisition of contrast-enhanced turbo fluid-attenuated inversion recovery (FLAIR) MR images is very useful for the diagnosis of meningeal involvement in CNS infections. Familiarity with imaging findings of the different infectious diseases and their complications is very important as early diagnosis and recognition of complications may reduce morbidity and mortality. In this chapter, we review the imaging findings of CNS infections and their potential complications.