Various studies have investigated the temporal aspects of non native speech and their relation to perceived fluency, because fluency constitutes an important aspect of second language proficiency. For this purpose it is important to determine which measures are most strongly correlated with perceived fluency and how these measures vary. In the present study objective measures related to perceived fluency were calculated for read and spontaneous speech of non-native speakers of Dutch. The results indicate that the objective measures vary as a function of different variables. Suggestions are made for future investigations so as to facilitate comparisons between studies and meta-analyses.