Introduction and Objectives: Left ventricular hypertrabeculation/non-compaction (LVHT) is a cardiac abnormality characterized by prominent trabeculations and intertrabecular recesses, and frequently associated with neuromuscular disorders (NMD). The aim of the study was to assess the prevalence of electrocardiographic (ECG) abnormalities in LVHT and its association with clinical symptoms, left ventricular size, wall thickness, systolic function, location and extension of LVHT and presence or absence of NMD. Methods and Results: In 86 patients LVHT was diagnosed echocardiographically between June 1995 and December 2004 (21 female, 65 male, age: 14–94 years, mean age: 52 ± 14 years). All patients underwent a baseline cardiologic investigation and were invited for a neurologic investigation. A specific NMD was diagnosed in 21 (metabolic myopathy, n = 14; Leber’s hereditary optic neuropathy, n = 3; myotonic dystrophy, n = 2; Becker muscular dystrophy, n = 1; Duchenne muscular dystrophy, n = 1), a NMD of unknown etiology in 32, the neurologic investigation was normal in 13, and 20 patients refused. Only 9 patients (10%) had normal ECGs. Frequent ECG abnormalities were tall QRS complexes (43%); ST/T-wave abnormalities (37%) and left bundle branch block (20%). ECG abnormalities were related with symptoms of heart failure and echocardiographic findings of systolic dysfunction and valvular abnormalities. Only atrial fibrillation (9%) was related to extension of LVHT. ECG abnormalities did not differ between patients with and without NMD. Conclusion: ECG abnormalities are frequent in LVHT. A normal ECG, however, does not exclude LVHT. No ECG pattern is typical for LVHT. ECG abnormalities occur independently of presence or absence of NMD, and thus all patients with LVHT should be referred to the neurologist.