Background Transthoracic echocardiography (TTE) is a commonly requested ICU investigation. Despite this, limited data exist regarding the diagnostic yield of unselected TTEs in a heterogenous ICU population. Methods A retrospective, cross-sectional, single-center study was performed. All ICU patients admitted from January 2018 to February 2019 were included. Aims The primary aim was to define the indications for, and diagnostic yield of, TTEs performed in the ICU. We also investigated the association between major abnormalities identified on TTE and mortality. Results There were 358 patients admitted to the ICU during the study period. Of these patients, 115 (32%) had a TTE performed during their ICU stay. The primary indication was to assess left ventricular function. Just under two-thirds of TTEs (65%) were normal or had minor abnormalities. Compared to the rest of the ICU population in our study (including both patients without a TTE performed and patients with a normal TTE), patients with an abnormal TTE had higher ICU (35.9% vs 21.3%, Odds Ratio [OR], 2.06; 95% CI, 1.02-4.19, P = .04) and in-hospital (43.6% vs 30.3%, OR, 2.64; 95% CI, 1.33-5.25, P = .01) mortality. Conclusions A formal TTE was performed in one-third of patients during their ICU admission. Major abnormalities were identified in over one-third of these TTEs. ICU and in-hospital mortality were higher in patients with an abnormal TTE.