Blastocystis sp. is one of the most common intestinal parasites diagnosed worldwide, but its pathogenic role is still regarded by some authors as controversial. The frequency of Blastocystis sp. was studied during a two year period of time and its association with some clinical symptoms. An observational descriptive study was carried out from January 2012 to December 2013. A total of 3140 stool samples were investigated for the presence of parasites by various parasitological techniques. Among 3140 analyzed stool samples the prevalence of Blastocystis infection observed was 3.54%, the fourth most prevalent. A total of 111 stool samples were positive for Blastocystis sp., and 71 samples showed co-infection with one or more other intestinal parasites. The group of 5 to 14 years age group showed a higher percentage of infections in the group of symptomatic persons than in asymptomatic ones and it was statistically significant, while in persons with ages more than 40 years the frequency of infection with this parasite was higher in asymptomatic persons. Blastocystis infection is one of the most frequent parasitic infections diagnosed in our setting. The relationship with symptomatology found in individuals infected with Blastocystis was significant and this association was higher in younger children.