The impact of staff turnover during cardiac procedures is unknown. Accurate inventory of sharps (needles/blades) requires attention by surgical teams, and sharp count errors result in delays, can lead to retained foreign objects, and may signify communication breakdown. We hypothesized that increased team turnover raises the likelihood of sharp count errors and may negatively affect patient outcomes.All cardiac operations performed at our institution from May 2011 to March 2016 were reviewed for sharp count errors from a prospectively maintained database. Univariate and multivariable analyses were performed.Among 7264 consecutive cardiac operations, sharp count errors occurred in 723 cases (10%). There were no retained sharps detected by x-ray in our series. Sharp count errors were lower on first start cases (7.7% vs 10.7%, P < .001). Cases with sharp count errors were longer than those without (7 vs 5.7 hours, P < .001). In multivariable analysis, factors associated with an increase in sharp count errors were non-first start cases (odds ratio [OR], 1.3; P = .006), weekend cases (OR, 1.6; P < .004), more than 2 scrub personnel (3 scrubs: OR, 1.3; P = .032; 4 scrubs: OR, 2; P < .001; 5 scrubs: OR, 2.4; P = .004), and more than 1 circulating nurse (2 nurses: OR, 1.9; P < .001; 3 nurses: OR, 2; P < .001; 4 nurses: OR, 2.4; P < .001; 5 nurses: OR, 3.1; P < .001). Sharp count errors were associated with higher rates of in-hospital mortality (OR, 1.9; P = .038).Sharp count errors are more prevalent with increased team turnover and during non-first start cases or weekends. Sharp count errors may be a surrogate marker for other errors and thus increased mortality. Reducing intraoperative team turnover or optimizing hand-offs may reduce sharp count errors.