Despite the rapid expansion of legalized gambling, few social workers are trained to identify problem gambling symptoms. This study explored gambling knowledge, behavior, and problem symptoms in a sample of 1,777 clinical social workers through an online survey. Findings indicate about 77% of social workers gambled and more than 4% of those who gambled reported at least one problem gambling symptom. Participants answered less than half of the knowledge questions correctly, and a majority were unaware of the current diagnostic classification for gambling disorder or the legal age for gambling. Results of a multivariate regression analysis found that social workers in practice 8 to 15 years, employed in substance treatment facilities or universities, and/or with training in gambling treatment had higher levels of knowledge about gambling and gambling treatment. Findings underscore the need for social work schools and organizations to prioritize education and training for problem gambling identification and treatment.