The present study investigated behavioral activation (BA) bibliotherapy as a treatment for late-life depressive symptoms. BA bibliotherapy was administered using Addis and Martell's (2004) Overcoming Depression One Step at a Time as a stand-alone treatment that was completed by participants over a 4-week period. Results of an immediate intervention group were compared with those of a delayed treatment control group and treatment response for both groups was evaluated at 1-month follow-up. Results showed that symptoms on a clinician-rated measure of depression were significantly lower at post-treatment for those who received immediate BA bibliotherapy compared with those who were in the delayed treatment control condition. However, differences between groups at this period on a self-reported measure of depressive symptoms were not significant. Within-subjects analyses examining both treatment groups combined showed that clinician-rated depressive symptoms significantly decreased from pre-treatment to both post-treatment and 1-month follow-up. Self-reported depressive symptoms were significantly lower, and self-reported engagement in pleasant events was significantly higher, from pre-treatment to 1-month follow-up. These findings suggest that BA may be useful in treating mild or subthreshold depressive symptoms in an older adult population.