The longnose gar (Lepisosteus osseus) is a primitive predaceous fish common throughout much of the east central United States, but research on its age and growth in lacustrine systems is rare. To characterize gar age and growth, I used bowfishing to collect spawning longnose gar in spring 2010 from littoral zones at Lake Arrowhead, Clay County, Texas. Females were older than males but significantly exceeded males in total length and mass when age was controlled. Von Bertalanffy growth curves suggested that males had faster growth rates, smaller maximum lengths, and shorter life spans than did females. However, females were always longer than males at any given age. Bowfishing capture beyond distances of 9 m was biased toward larger fish, but the method was viable for collecting spawning longnose gar at close range. This study will assist fisheries managers and aquaculturists by providing growth—age relationships for longnose gar in a southern lacustrine system.