The purpose of this study was to construct and validate an orthographic processing task. Three hundred and twenty-five monolingual German speaking Austrian children from last year of nursery school to the second half of second grade took part.An orthographic word likeness task with 72 pairs of pseudowords was constructed and presented in four different versions: 1a in upper case letters (e.g. ZUSSER/ZUUSER), 1b in lower case letters (e.g. zusser/zuuser), 2a only one item of each pair in upper case letter, 2b in lower case letters. Items were constructed so that doublets occurred either in legal positions or in illegal positions. In the latter condition half of the items consisted of high frequent doublets and the other half of less frequent doublets (e.g., mm versus ww).Versions 2a and 2b did not differentiate between grades and between good and poor readers within each grade. Therefore, versions 2a and 2b were not further analyzed.On average, items were too difficult for nursery school children and too easy for second graders. Only for first graders the item difficulties were suitable.Nursery school children are able to differentiate between pseudowords with common letter doublets and pseudowords with uncommon letter doublets (frequency items). In contrast, they cannot distinguish between pseudowords with letter doublets in allowable and unallowable positions (position items).First graders are able to differentiate between both, frequency items and position items, as long as mono-syllabic position items are used. In second grade, children can also perform multi-syllabic frequency and position items.Correlation analyses revealed a moderate and significant relationship between performance in the orthographic word likeness task and letter knowledge in kindergarten. Task performance correlated highly with orthographic spelling in Grade 1, and there was a tendency for a significant association between orthographic word likeness and spelling in Grade 2.