Mashua is an edible-tuber crop that grows in the Andean region. Folk medicine describes the use of mashua to reduce reproductive function in men. The present study aimed: (i) to determine whether different doses of mashua (0.01, 0.1, 1 and 2gkg -1) produced a dose-response reduction on sperm production and quality; and, (ii) to determine whether these anti-reproductive effects of mashua can be reversible after cessation of treatment (12 and 24days of recovery time). Mashua-treated rats showed lower values of daily sperm production, epididymal and vas deferens sperm count and sperm motility; meanwhile, mashua increased the percentage of abnormal sperm morphology and epididymal sperm transit rate. The following variables follow a dose-response effect: sperm number in vas deferens, sperm motility and sperm transit rate. In addition, it was demonstrated that the reduction in reproduction function in male rats treated with mashua was reversible after 24days of recovery time. Finally, lower doses mashua reduces sperm number and quality (motility and morphology), and these adverse effects on male reproductive system may be reversible after 24days after cessation of the treatment. © 2011 Blackwell Verlag GmbH.