Nanoscale metal-organic frameworks (MOFs) have been widely used as controlled drug delivery vehicles and cancer therapy agents due to their intrinsic superior properties. Scientists have made remarkable achievements in the field of nanomedicine by using the MOFs and MOF-based multifunctional nanomaterials due to the easy synthesis into nanoscale and functionalization. In this review, we highlight the recent progress of nanoscale MOFs as drug delivery vehicles for cancer theranostics. We divide the discussion into three parts. The first and second parts focus on the drug delivery of unmodified MOF and modified MOFs, respectively, while the third part focuses on porphyrin MOFs as photosensitizers for photodynamic therapy. Finally, we conclude by identifying areas of research that we believe will propel the translation and application of MOFs.