Giardiasis is a parasitic infection of the digestive tract, most commonly occurring in closed communities such as schools, kindergartens, prisons, and campuses. The civil war in the former Yugoslav republics and in Kosovo caused a large number of refugees to take shelter in the territory of Serbia. Such large numbers of refugees could be accommodated only in the collective centers. Our aim was to examine the differences in the prevalence of asymptomatic giardiasis among 122 refugees from the former Yugoslav republics who lived in the collective centers in Nis, Serbia, and 241 native Nis inhabitants. Conventional microscopic examination (CME) of three stool samples with or without concentration technique and the enzyme immunoassay (EIA) methods were used. The CME method of three stool samples is considered the gold standard in our statistical survey. Asymptomatic giardiasis is found in 7 refugees (5.7%) using the EIA method, while using the CME (3 samples) Giardia duodenalis (G. duodenalis) was detected in 6 persons (4.9%). Using the EIA method and the CME (3 samples) G. duodenalis was detected in only 1 person in the population group of native inhabitants (0.4%). Asymptomatic giardiasis was more prevalent in the population group of refugees accommodated in collective centers than in native inhabitants in the Nis municipality, Serbia.