The assignment of stress when reading Greek can be based on lexical and orthographic information. One hundred and seventy seventh-grade children read lists of isolated words and pseudowords. A large proportion of stress assignment errors were made in pseudoword reading, especially on the items that do not follow the most frequent penultimate stress pattern. Analysis of text corpora indicates that ignoring written stress diacritics would result in less than 1% errors, without taking into account disambiguating effects of context. It is tentatively suggested that, in reading Greek, stress assignment is primarily lexical. The results are consistent with a hypothesis that the bisyllabic trochee is the default metrical frame in Greek.