Patients with a REM sleep behavior disorder have an increased risk of developing Parkinson’s disease in the future. As speech production is a sensitive domain that can provide early information about deviations in motor control, we follow the question if speech might function as prodromal biomarker for Parkinson’s disease. Therefore, we compare speech movements of healthy control speakers, patients with isolated REM sleep behavior disorder and patients with Parkinson’s disease to investigate which speech domain might distinguish these groups. We carry out articulatory and acoustic recordings (electromagnetic articulograhy) to observe the spectro-temporal characteristics in the speech signal and the underlying articulatory movements of tongue, lips and jaw.