Whipple' disease is mainly characterized by affecting the digestive system, although it can be a multisystemic process with different clinical symptoms. The bacillus causing the disease has been isolated and cultivated in 2000 and the genome sequence has been recently analyzed in 2003, which means new perspectives for its diagnosis and treatment. Giardiasis is an infestation caused by a protozoo and may cause a malabsorption syndrome or run in a subclinic way. The case of a middle-aged male is described, who after a three-year period of migratory arthralgias, showed weight loss, diarrheas and abdominal pain, being diagnosed of Giardiasis, and after the persistent symptoms and a number of studies, was diagnosed with Whipple disease. Nineteen cases of Giardia-Whipple coinfection have been described in the literature, but the reason of this association has not been found yet. The discussion on whether there is an alteration in the immunitary system which facilitates infections or, the development of an infection lead to the other one, goes on.