Some demonstrative embodiments include apparatuses, devices, systems and methods of communication based on Clear Channel Assessment (CCA) in one or more directions. For example, an apparatus may include logic and circuitry configured to cause a wireless station to determine a plurality of directions to transmit a plurality of respective data streams of a Multi-Input-Multi-Output (MIMO) transmission; to detect a plurality of CCA states corresponding to the plurality of directions, respectively; and based on the plurality of CCA states, to transmit one or more selected data streams of the plurality of data streams in one or more respective selected directions of the plurality of directions.