The current study was first to describe distinct patterns of prosody that discriminate motivationally laden speech. To do this we applied self-determination theory, a widely used motivational framework. Participants in the US and UK were asked to read out loud either autonomy-supportive sentences (that support choice and volition) or controlling (pressuring and coercive) sentences. Data analyses were conducted using a conservative hierarchical linear modeling approach to account for nesting of sentences within individuals. Across both countries and controlling for gender, autonomy-supportive sentences were read using lower pitch, less intensity, and a slower speech rate than were controlling sentences. Multiple regression analyses showed links between these patterns of prosody for each participant and his or her current level of motivation, providing additional validity to results. Findings inform both the motivation and prosody literatures and offer a first description of how different kinds of motivational speech may sound.