This study aimed to investigate different echocardiographic parameters for predicting atrial fibrillation (AF) in patients with transient ischemic attack (TIA). Echocardiography was performed in 110 patients (median age 65.8 years, 53% males) with TIA and no history of stroke or AF. All patients underwent monitoring with ECG and 72 h Holter-monitoring, and if no AF was found, an insertable cardiac monitor (ICM) was implanted and patients were followed for a median of 2.2 years. AF was found in 14 patients: five with Holter-monitoring and nine with ICM. AF patients had significantly larger left atrial (LA) volumes indexes compared to patients without AF (26.7 vs. 33.7 ml/m², P = 0.03 for 2D images and 26.5 vs. 33.5 ml/m², P = 0.0008 for 3D images). Patients with AF also had depressed LA function assessed with LA emptying fraction measured with 2D echocardiography (46.3 vs. 57.3%, P = 0.005 for patients with and without AF, respectively). Patients with AF also had depressed left ventricular (LV) function compared to patients without AF. LV ejection fraction was 55 versus 61%, P = 0.04 in patients with and without AF, respectively. LV global longitudinal strain (absolute value) was 16.7 in patients with AF compared to 21.2 in patients without AF (P = 0.001). Echocardiographic measurements of LA and LV size and function can noninvasively predict AF in patients with TIA and could potentially be used to guide AF monitoring strategy.