Associations between environmental variables and reproductive condition of six catostomid (family Catostomidae) species were evaluated in the Baraboo River, Wisconsin. Electrofishing and hoop net surveys conducted from Mar. to Jun. of 2001 and 2002 revealed white sucker (Catostomus commersoni) reached spawning condition first, followed by quillback (Carpiodes cyprinus) in both years. These two species were followed by the overlapping spawning times of spotted sucker (Minytrema melanops), golden redhorse (Moxostoma erythrurum), shorthead redhorse (M. macrolepidotum), and silver redhorse (M. anisurum). The first axis of a principal component analysis (PCA; based on six environmental variables) explaining 47% of the variation in the environmental variables represented water temperature, flow, and day of the year. The second axis explaining an additional 26% of variation depicted the magnitude of shorter-term changes in water temperature and flow. The best-fitting multinomial logit model to explain variation in reproductive condition of white sucker, shorthead redhorse, and silver redhorse included the first two PCA axes, species, year, and sex along with several first order interactions as predictor variables. The model predicted general temporal trends in reproductive condition over the spawning season but sampling noise precluded the model from identifying fine-scale temporal variation in spawning. Temporal variation in catostomid reproductive condition appears to be driven by complex interactions among species and environmental cues.