A recording and/or reproducing method, a recording and/or reproducing apparatus, and a computer readable recording medium storing a program for performing the method. A recording unit block in which invalid data is partially padded is written on an information storage medium along with padding information indicating that the invalid data is included in the recording unit block. The padding information is useful in determining whether the recording unit block includes the padding data. Accordingly, unnecessary retrial processes of a drive system are reduced such that the performance of the drive system is improved and error correction capability is enhanced.