Objective: Investigate symptoms and how they affect daily life in patients with Non-Muscle Invasive Bladder Cancer (NMIBC) treated with Bacillus Calmette-Guerin (BCG) instillations. Materials and methods: Patients treated with BCG were included. After an initial transurethral resection (TURB) followed by a second-look resection, the patients were given an induction course with BCG for 6 weeks followed by maintenance therapy for 2 years. The patients answered a questionnaire before, during and after the treatment. The questionnaire contained questions about specific symptoms combined with bother questions on how each symptom affected patients life. Results: In total, 113 of 116 patients responded to the first questionnaire. Thirty per cent of all patients were bothered by disease-specific symptoms before the start of BCG. Few patients reported fever, haematuria, illness or urinary tract symptoms. No difference in symptoms was found between patients with or without concomitant CIS (carcinoma in situ). Patients younger than 65 years of age reported a greater worry about the symptom burden in the future than those who were older. Patients younger than 65 years reported a decreased level of mental well-being. Conclusion: Patients with bladder cancer T1G2-G3 had disease-specific symptoms present already before the start of the BCG. The burden of symptoms was reduced over time and showed that the bladder might recover. BCG instillations had side-effects that negatively affected the patients well-being. It is important to record the patients baseline bladder and voiding status before as well as during the BCG-instillation period in order to understand symptoms caused by the treatment.