To investigate the trends in incidence and long-term recurrence rate of pilonidal sinus disease (PSD) within the German Armed Forces, and analyse the influence of variable factors, such as different surgical methods, body constitution and smoking amount, to incidence and long-term recurrence rate of PSD.Information of all the patients being admitted with primary PSD to the surgical departments of three hospitals of the German Armed Forces between 1980 and 1996 was collected and analyzed, 500 patients of which were interviewed.Two of the 500 patients were dead, and every one of the rest 498 patients agreed to take part in the interview. The incidence of PSD rose from 0.3/1000 in 1985 to 2.4/1000 in 2007. The recurrence rates were decreasing within 16 years of treatment from 33% in 1981 via 23% in 1986 to 12% in 1996 (P = 0.01). Recurrence rates of primary open wound healing (16.8%) compared to primary suture (31.0%) differ significantly (P < 0.01). While the mean body weight within the army rose 1 kg per decade, population shows an increase of 1.9 kg per decade though not being an influencing factor on the recurrence rate (P = 0.72). Smoking of more than 20 cigarettes per day proved to be a significant factor on the recurrence rate of PSD (P = 0.015).While the recurrence rates-especially of primary open wound treatment-decreased, the incidence of PSD rose nearly tenfold.