Objective[|]The aim of this retrospective study was to evaluate demographic, etiologic and epidemiologic characteristics, and clinical and laboratory findings of Henoch-Schonlein purpura (HSP) and to determine risk factors increasing the kidney involvement in our region.[¤]Materials and Methods[|]Records of 151 patients who were followed-up with the diagnosis of HSP between May 2002 and December 2010 in the Department of Child Nephrology in Kocaeli University Medical Faculty and fulfilled the inclusion criteria were retrospectively evaluated. Demographic characteristics of the patients, season of presentation, complaints on admission, triggering factors, pathological examination, laboratory data, and the duration of follow-up periods were assessed.[¤]Results[|]Of 151 patients, 90 (60%) were male and 61 (40%) were female. The mean age was 7.4±3.4 years (range, 1.8-16.5 years). While 33 (22%) patients did not have purpuric rash on admission, they were then observed to have purpuric rash during the follow-ups. Increasing age was found to be a risk factor for kidney involvement (p=0.011). Testicular involvement was identified as a negative risk factor for kidney involvement (p=0.020). Factors such as gender, GIS and musculoskeletal system involvement, recurrence, and steroid treatment were not found to be associated with kidney involvement.[¤]Conclusion[|]Etiologic, epidemiologic, and clinical findings of HSP patients in our region were found to be similar to those reported in the national and international studies. In parallel to the literature, the present study showed an increased risk of kidney involvement with increasing age.[¤]