A method for preventing read-disturb errors, a memory storage apparatus and a memory control circuit unit are provided. The method includes counting an operation numerical value when receiving an operation command from the host system, wherein a first physical erasing unit is selected for executing the operation command. The method also includes selecting a second physical erasing unit and reading data from the second erasing unit. The method further includes determining whether a data error occurs at the second physical erasing unit according to the data read from the second physical erasing unit, and if the data error occurs, selecting a third physical erasing unit, correcting the data read from the second physical erasing unit to generate corrected data and writing the corrected data into the third physical erasing unit.