Background: The dyshomeostasis of trace elements is associated with multiple organ dysfunction in patients with septic shock. However, it remains unclear whether the change of whole blood copper (Cu) and zinc (Zn) levels influence cardiac function in patients with septic shock. Here, we sought to explore relationship between whole blood Cu and Zn and cardiac dysfunction in septic shock. Methods: Between April 2018 and March 2020, septic shock patients with sepsis-induced left ventricular systolic dysfunction (SILVSD, left ventricular ejection fraction, LVEF < 50%) and with no sepsis-induced myocardial dysfunction (non-SIMD, septic shock alone and LVEF> 50%) on an intensive care unit (ICU) in south China and healthy controls were prospectively enrolled. whole blood Cu and Zn levels were measured using flame atomic absorption spectrophotometry.Results: 86 patients with septic shock including 41 SILVSD and 45 non-SIMD and 25 healthy controls were studied. Whole blood Cu levels were significantly higher and Zn were significantly lower in SILVSD compared with non-SIMD and controls [Cu, (16.34±1.93) vs. (15.23±2.07) vs. (14.02±1.65) µmol/L, p = 0.009, < 0.001; Zn, (78.45±12.18) vs. (85.07±14.80) vs. (94.90±14.78) µmol/L, p = 0.029, < 0.001]. Both increased whole blood Cu and reduced Zn were associated with lower LVEF ( all p < 0.001) and higher amino-terminal pro-B-type natriuretic peptide (NT-proBNP) (Cu, p = 0.002, Zn, p = 0.001), and had predictive values for SILVSD [Cu, (AUC = 0.666; p = 0.005) ; Zn, (AUC = 0.625; p = 0.039)]. Whole blood Cu levels were increased but Zn were reduced in non-survivors compared with survivors[Cu, (17.20 ±2.25) vs. (14.99 ±1.49) µmol/L, p < 0.001; Zn, (71.17 ±11.98) vs. (87.67±11.30) µmol/L, p < 0.001],. Whole blood Cu and Zn displayed the value of predicting 28-day mortality [Cu (AUC = 0.802, p < 0.001); Zn (AUC = 0.869, p < 0.001)].Conclusions: Whole blood Cu levels were increased in SILVSD patients and positively correlated with the cardiac dysfunction while Whole blood Zn were reduced and negatively associated with the cardiac dysfunction. Moreover, both whole blood Cu and Zn could distinguish between SILVSD and non-SIMD in septic shock patients and predict 28-day mortality.Trial registration: ChiCTR1800015709. Registered 16 April 2018, http://www.chictr.org.cn/edit.aspx?pid=26746&htm=4.