We report the visible-light-promoted photocatalytic activity of a highly porous carbazolic organic framework, Cz-POF-1, toward three prototypic organic transformations: net reductive dehalogenation of phenacyl bromide and its derivatives, net oxidative hydroxylation of arylboronic acids, and redox-neutral alpha-alkylation of aldehydes. We show that the extended p-conjugation in Cz-POF-1 enhances its visible light absorption, and the large porosity accelerates the reaction rate. For alpha-alkylation of aldehydes, Cz-POF-1 requires less strict reaction conditions and can be easily recovered and reused for up to 10 times. This work reveals a bright future for Cz-POFs as a new generation of metal-free photocatalysts for organic synthesis.