Automatic speech recognition systems apply grapheme-tophoneme transcription (G2P) to model pronunciation of items in the lexicon. General purpose G2P transcriptions are not always accurate, e.g., in a multilingual environment. To improve the transcription quality, G2P transcriptions can be postprocessed using a phoneme-to-phoneme (P2P) converter. This paper discusses the applicability of P2P technology based on results of a speech recognition experiment using P2P conversion on a multilingual speech corpus. P2P conversion can be applied successfully, however the analysis also shows limitations of P2P technology.