Older adults with insomnia were recruited from the community and randomized to treatments: relaxation, sleep compression, and placebo desensitization. Questionnaire data collected at baseline, posttreatment, and 1-year follow-up and polysomnography data collected at baseline and follow-up yielded the following conclusions: All treatments improved self-reported sleep, but objective sleep was unchanged. Clinical significance analyses yielded the strongest findings supporting the active treatments and suggested that sleep compression was most effective. Results partially supported the conclusion that individuals with high daytime impairment (i.e., fatigue) respond best to treatments that extend sleep, as in relaxation, and individuals with low daytime impairment respond best to treatments that consolidate sleep, as in sleep compression. Strong methodological features including a placebo condition and a treatment implementation scheme elevate the confidence due these findings.