There is an increasing public interest about the harmful effects of agricultural practices on the environment. This fact has promoted the sustainable crop production, especially regarding fertilization. Vermicompost is an organic fertilizer that has gained importance as a nutritional source as well as a component of horticultural crop substrate. The aim of the current study was to establish a rate for a Vermicompost: Sand (VC:S) mixture that increases yield and antioxidant capacity in cucumber fruits (Cucumis sativus L.) produced under greenhouse conditions. These VC:S rate treatments were evaluated: 25:75, 30:70, 35:65, 40:60 and 45:55. On average, lower vermicompost percentage (25-30%) showed higher yield (1883 g pl-1) than using higher ratios (738 g pl-1), with the additional advantage of presenting fruits with higher antioxidant capacity (increases of 43%). The use of vermicompost has proven its potential as an alternative nutritional source for organic production of cucumber under greenhouse conditions. Besides, there are benefits of producing organic cucumbers with high antioxidant capacity, since that provides a higher competitive marketing advantage for producers, while the application of chemical compounds is reduced, contributing to protect the environment.