Because of its regularity, it is relatively easy to learn to read and spell in Finnish. However, a specific hurdle in spelling acquisition seems to be the doubling of consonant letters. In this study on consonant letter doubling spelling in Finnish children (91 Grade 1 and 191 Grade 2 children), we asked two questions. First, are items with double consonant letters (e.g., “kissa” [ˈkisːɑ] ‘cat’) indeed harder to spell than single consonant items (e.g., “kisa” [ˈkisɑ] ‘contest’)? Second, is consonant doubling harder for stop consonants (e.g., “takki” [ˈtɑkːi] ‘coat’) than for continuant consonants (e.g., “kissa” [ˈkisːɑ] ‘cat’)? We found that Finnish children made more errors on items with double consonant letters than on items with single consonant letters and that this effect was larger for stop than for continuant consonant letters. Exploratory analyses showed that these effects were stronger for younger and poorer spellers. Post hoc analyses of the errors made on double consonant items showed that the children predominantly made nonlexical errors (> 90%). When they did make a lexical error, these errors typically did not map on the type of errors that would be expected from a corpus analysis of the higher-frequency orthographic neighbors. Overall, lexical influences on spelling of Finnish children seem to be minimal and unpredictable. We discuss two potential reasons why it is more difficult to spell items with double consonant letters than with single consonant letters and suggest how these could be investigated in future research.