Three-dimensional porous crystalline polyimide covalent organic frameworks (termed PI-COFs) have been synthesized. These PI-COFs feature non- or interpenetrated structures that can be obtained by choosing tetrahedral building units of different sizes. Both PI-COFs show high thermal stability (>450 degrees C) and surface area (up to 2403 m(2) g(-1)). They also show high loading and good release control for drug delivery applications.