Intestinal parasitic infections or infestation are amongst the most prevalent infections worldwide. This study aimed at revealing the changing trends over a decade duration of intestinal parasites identified at a major tertiary care center in Lebanon between 1997-1998 and 2007-2008. The total number of specimens tested were 14,771 for 1997-1998 vs 7477 for 2007-2008. The positive findings for parasites were 2077 (14%) vs 1047 (14%), respectively. The majority of recovered parasites in both study periods belonged to intestinal protozoa (91% and 95%), followed by cestodes (6% and 3%), and nematodes (3% and 2%), while trematodes were negligible in both periods. The highest prevalence occurred among ages 16 to 35 years for 1997-1998, and without age predominance in the second period. The detected parasites from 1686 individuals (11.4%) in the first period vs 904 (12.1%) in the second period encompassed 18 species. The most common "pathogenic" parasite in both periods were: Entamoeba histolytica (14% vs 12%), Giardia lamblia (16% vs 6%), Taenia spp. (6% vs 3%), and Ascaris lumbricoides (2% vs 1%). Generally, these were detected more in males than females, in adults than in children, and during the summer (= 30%) and autumn (= 26%) than winter (= 20%) seasons for both periods. Despite some observable decrease in prevalence among the two study periods, sustainability of substantial intestinal parasites detection continues to exist. The latter is a valuable indicator for a state of collective ill-health, warranting more attention and efforts for public health awareness to improve hygiene and sanitation in order to minimize the prevalence of these parasites in this country.