A method of performing a read operation in a flash memory device is disclosed. The flash memory has a memory cell array including at least one block, the block having a plurality of pages. The method comprises receiving a read command to read data from a selected page in the block; determining whether or not the block has any page that has not been programmed; performing a dummy data program operation on at least one page that is determined not to have been programmed; and executing the read command to read the data of the selected page after the dummy data program operation is completed.