The objective of this paper is to examine the comparability level in financial reporting before and after the introduction of the 1990 General Accounting Plan (GAP) in order to quintify the possible harmonization got by the standard. Specially, the leasing operations, the foreign currency exchange and the interest capitalization are analyced. The results show thatm in general, in spite of the increasing in the amount of information reported the comparability has decreassed after the introduction of GAP due to the flexibility permitted by the standard, thas ins, some desharmonization in the studied items has been detected.