The spawning behavior of male and female largemouth bass Micropterus salmoides (Lacépède) was studied in central Illinois during the spring of 1998 to examine patterns of muscular activity associated with different spawning related behaviors and to evaluate whether electromyogram (EMGi) telemetry could be used to detect spawning activity. Fish were implanted with EMGi transmitters (8 females, 16 males) on April 7, prior to the initiation of spawning, and were released in four 0.10‐ha earthen research ponds. Continuous EMGi records, underwater videography and additional visual observations for one pair of EMGi tagged fish were collected throughout the entire spawning event, allowing us to quantify behavioral correlates of physical activity. Male EMGi activity patterns were only correlated with female patterns during courting and periods of male aggression toward the female. Overall, EMGi activity was highest for the female during shuddering (gamete deposition), whereas male EMGi activity was similarly high during periods of nest excavation, shuddering and post‐spawn parental care activities. During spawning, female EMGi activity was positively correlated to shuddering. Average daily EMGi activities for females peaked on the day of spawning. As a result of their engagement in parental care activities, male activity continued to rise even after spawning was completed. EMGi telemetry appears to be a useful technique for monitoring the reproductive activity of largemouth bass, especially in areas of high cover or turbid water or during low light conditions. This technology permitted us to quantify and contrast the activity patterns associated with different spawning related activities, information that will be required to construct accurate, gender‐specific bioenergetics models for this species.