We used event-related potentials (ERPs) and acoustic analyses to investigate the processing of prosodic pitch accents as a function of their position in a sentence. Accents in sentence-medial positions were characterised by a higher fundamental frequency (F0) and an increased duration. They elicited negative ERP components around 400 ms. When the accent was predictable, this negativity was fronto-laterally distributed and identified as the previously known Expectancy Negativity. Unpredictable accents elicited a more broadly distributed N400 with a central maximum, reflecting difficulties in semantic processing. In contrast, words with sentence-initial pitch accents had a higher F0 but of the same duration as in words without pitch accents. These pitch accents elicited a P200 but no negativity at a 400 ms time window. The P200 was modulated by the onset latency of the F0 peak rather than its magnitude. We discuss the possibility of a delayed processing of sentence-initial accents when the actual occurrence of an F0 peak can be identified by comparison with a subsequent reduced pitch shape in the signal.