Glucosinolates (GSL) present in cultivated and feral accessions of mashua (Tropaeolum tuberosum Ruíz & Pavón) were identified and quantified by High Performance Liquid Chromatography (HPLC) analysis. The main glucosinolates detected were aromatic: 4-Hydroxybenzyl GSL (OHB, Glucosinalbin), Benzyl GSL (B, Glucotropaeolin), and m-Methoxybenzyl GSL (MOB, Glucolimnathin). The total amount of GSL observed ranged from 0.27 to 50.74 micromols per gram (μMol/g) of dried tuber tissue. Most of the low-content GSL accessions are distributed within the cultivated population with a total GSL concentration lower than 5.00 μMol/g of dried tuber tissue. The highest total and specific GSL (OHB, B, and MOB) contents (more than 25.00 μMol/g of dried tuber tissue) were observed in the feral population with few exceptions. In addition, only six different GSL profiles were found: Only MOB; only B; OHB and B; OHB and MOB; B and MOB; and OHB, B and MOB. © 2006, by The New York Botanical Garden Press.