RationaleThe European Position Paper on Sinusitis (EPOS) guidelines provide composite criteria to evaluate chronic rhinosinusitis (CRS) control, taking into consideration the severity of patients’ symptoms, aspect of nasal mucosa and medical intake as parameters of CRS control.ObjectivesTo study the degree of CRS control using novel EPOS control criteria at 3–5 years after a functional endoscopic sinus surgery (FESS) and correlate these data to symptoms scores.MethodsAdult CRS patients (n = 560) who had undergone bilateral FESS for chronic inflammatory sinonasal disease 3–5 years prior to the study were included. Patients received a postal questionnaire asking for control items according to EPOS control criteria, visual analogue scale (VAS) scores for total and individual sinonasal symptoms, sinonasal outcome test (SNOT)‐22 and Short Form (SF)‐36 questionnaires.Measurements and main resultsAbout 19.5% of CRS patients were well controlled, with 36.8% of patients being partly controlled and 43.7% uncontrolled. The levels of control corresponded to mean total VAS, SNOT‐22 and SF‐36 scores. Subgroup analysis revealed that female gender, aspirin intolerance and revision FESS were associated with higher prevalence of uncontrolled CRS, whereas allergy, asthma and smoking status did not alter the percentage of patients in each category of control. In 81 patients attending the outpatient clinic, nasal endoscopy changed classification in only four patients (4.9%).ConclusionsBased on the novel EPOS control criteria, at least 40% of CRS patients are uncontrolled at 3–5 years after FESS. Therefore, better treatment strategies leading to higher disease control are warranted in CRS care.