Covert, or undercover, investigations have been utilized by various state and federal law enforcement agencies for decades to detect and prosecute surreptitious and organized forms of criminal activity. Historically, wildlife law enforcement divisions have relied almost exclusively on overt, or uniformed modes of enforcement, both as a means of effecting voluntary compliance, and to detect and prosecute instances of noncompliance. Modern technological advances coupled with increased commercial value of many wildlife species has generated clandestine and organized illegal commercial activities which can severely impact natural resources. Recent covert operations by state and federal wildlife agencies have proven effective in combating these types of violations. Some illustrative case examples are presented.