Agricultural activity is a feasible alternative in the Amazon as long as technologies are used to generate social, environmental and economic benefits without changing the ecology of the system. In the Amazon region has made ​​work that showed different distribution, geographic presence and incidence of various parasitic genera that affect cattle. The aim of the present study was to evaluate the association between age and protozoa in cattle under free grazing in Canton Arosemena Tola Province Napo - Ecuador. 147 cattle feces were sampled during March 2011 and November 2012. The collection of faeces was carried out during the early hours of the morning and were obtained directly from the rectum of the animal. Coproparasitological analyzes were performed at the Laboratory of Parasitological Diagnosis Vetetinario Chaco-Ecuador. Of the total number of sampled animals were divided into two groups: ≤ twelve months (31) and ≥ to twelve months of age (116). The relationship between protozoa and age was assessed with a test of homogeneity based on Chi-square statistics (P <0.05) and hypothesis test for continuous variables, Student t according to (P <0.05). In both types of parasites Coccidia and Balantidium are significant (Chi2 (P <0.0001) among children ages twelve months and older than twelve months. The protozoa coccidia especially their presence is more dangerous during the first year of life so positive that 20% of them in that period have no presence. Although a negative result is high percentage (58.1) in the presence of coccidia in cattle analyzed. also we should take into account not only the presence, but the parasite load is a necessary thing for an upcoming job. We conclude that there is an association between the presence of protozoa and age of cattle.