Field experiments is on spacing of Japanese mint (Mentha arvensis L., subsp. haplocalyx Briquet, var. piperascens Holmes or forma piperascens Malinvaud) were conducted at the experiment stations of Pindorama and Tietê, during the 1943-44, 1944-45 and 1950-51 seasons. In Brazil, nowadays the leading world supplier of menthol and dementholized oil, mint is generally raised in newly cleared forest soils. In these areas planting is usual|y done at irregular spacings, due to the presence of trunk and branches of the felled trees, the distances between plants being rather wide. Yields, recorded as fresh and cured (wilted) hay and oil, were significantly higher from the following spacings: 40 x 20, 50 x 20, 60 x 20 and 50 x 40 centimeters. Considerations on the amount of rhizomes and labor necessary for nurseries and transplanting were made when interpreting the experimental results. The relation was also discussed in regard to the best use of the land.