Background and study aim: Giardiasis is a gastrointestinal disease,
caused by the protozoan parasites Giardia lamblia. Thisinfection occurs through the ingestion of contaminated water or food by  Giardia lamblia cysts. The aim of this study was to correlate between the presence of Giardia lamblia and some physical measurements.
Subjects and methods: the experimental study was performed at the laboratories of Parasitology Department, Faculty of Medicine, Sohag University from October 2016 to October 2017. It was done on 93 patients, who had Giardia from different localities in Sohag governorate after examination of stool samples by saline and iodine wet mount. History taking and some physical measurements, like weight and height, using a meter, a scale and growth charts were taken for cases included in this study.
Results: There was a decrease in height, 50 (53.8%),  weight for height, 49 (52.7%), body mass index, 45 (48.4%), and weight, 33 (35.5%), of cases with Giardia lamblia infection by different proportions.