The objective of this study is to investigate factors leading to the development of umbilical pilonidal sinus (UPS). 31 patients with UPS treated at Harran University and Keçiören State Training Hospital between January 1997 and November 2007. 100 consecutive volunteer outpatients were administered questionnary. The questionnary included questions on age, sex, profession, body mass index (BMI), skin color, hirsute status, frequency of taking baths, personal history of pilonidal sinus (PS), familyal history of PS, and whether -they wear tight clothes and wheteher they use belt. The results obtained from two groups were compared. UPS is one of the PS group diseases and involves umbilical region. There was statistically significant difference between the patient and control groups in terms of age, profession, hirsute status, familial history of PS, wearing tight clothes and BMI. Improvement in these factors may contribute to the reduction of the prevalance of the disease.The online version of this article (doi:10.1007/s12262-010-0226-x) contains supplementary material, which is available to authorized users.