Seven plant species, used as traditional medicine, from two regions of Ecuador have been subjected to qualitative and cuantitative phytochemistry screening in order to provide information about possible chemical compounds present in these species that will contribute to future researchs. Chuquiraga jussieui J.F. Gmel., Pseudognaphalium elegans (Kunth) Kartesz (Asteraceae), Gustavia pubescens Ruiz & Pav. ex Berg (Lecythidaceae), Aeghiphila alba Moldenke (Lamiaceae), Cleome spinosa Jacq. (Cleomaceae), Phyllantus acuminatus Vahl (Phyllantaceae) and Croton rivinifolius Kunth (Euphorbiaceae) were the species selected for this investigation. Phytochemical determination was oriented to search for alkaloids, flavonoids, tannins, triterpenoids, steroids, saponins and anthraquinones. Total phenols and flavonoids content were measured on the crude ethanol extracts of all species assayed being Pseudognaphalium elegans and Chuquiraga jussieui the species with higher content of this class of compounds with 1362.08 ± 2.10 and 1979.07 ± 3.10 mg E Cat/100g dry extract and 130.69 ± 5.70 and 244.18 ± 9.80 mg E Querct/100 g dry extract, respectively. Results showed a close relation to the % inhibition of DPPH and IC50mg E Trolox/mL observed where P. elegans exhibited (56.4%;) 41.85 (± 0.07) and C. jussieui (58.2%) 41,02 (± 0.05). This is the first report on the chemical screening, total phenolics, total flavonoids and antioxidant activity of these species. According to references consulted Croton rivinifolius is endemic from Guayas province and has no reports either for phytochemical composition or antioxidant activity. © 2015, SILAE (Italo-Latin American Society of Ethnomedicine). All rights reserved.