Objective Triggering receptor expressed on myeloid cells (TREM)-1 is a receptor that is thought to improve recognition of patients with true infection. In this study, we investigated whether Triggering receptor expressed on myeloid cells (TREM-1) is present in urine samples from children with urinary tract infection (UTI) and in samples from healthy children. Methods A total of 128 samples met the inclusion criteria for the study. Urine samples were processed for culture and urinalysis as a regular protocol for patients with UTI. Samples were classified according to culture and urinalysis results. TREM-1 protein expression was detected with flow cytometry and sTREM-1 was assessed by ELISA. Results Flow cytometry showed detectable expression of TREM-1 in 100% of samples, UTI and non-UTI groups ( p