Purpose We determined the fluctuation of nocturia in a 12-month period in men with lower urinary tract symptoms. Materials and Methods Men with lower urinary tract symptoms were allocated to the placebo arm of the United States Department of Veterans Affairs Cooperative Studies Program Benign Prostatic Hyperplasia Study. Reported nocturia frequency using the American Urological Association Symptom Index was collected at 6 time points (2, 4, 13, 26, 39 and 52 weeks). Repeat measurements of nocturia during a 1-year period were analyzed using a generalized mixed linear model. Results Of the 305 men allocated to the placebo group 256 participants (84%) gave answers for all 6 time points. In the entire sample the mean nocturia count did not significantly vary from baseline (week 2) after adjusting for covariates (p = 0.542). However, there was considerable fluctuation in nocturia during 1 year. Of the 93 men with 3 or 4 episodes at baseline 47% had improvement and 12% had worsening at 1 year. Of the 184 men who reported 2 or greater nocturia episodes at baseline 15% reported 0 or 1 at 52 weeks. Depending on the case definition during followup the probability of nocturia progression varied between 8% and 54% while nocturia regression varied between 2% and 33%. Conclusions Using repeat questionnaire based assessments we observed considerable fluctuation in nocturia. However, overall there was no significant increase in prevalence in a 1-year period. These findings may be reassuring to providers and patients who elect to delay interventions for nocturia. © 2014 by AMERICAN UROLOGICAL ASSOCIATION EDUCATION AND RESEARCH, INC.