The study compares two different graphic marking systems designed to helpL2 learners of Swedish notice and realize phonological length. In System A,22 L2 learners read aloud three /VːC/ words with length marked under longvowels and three /VCː/words with dots under short vowels. Twenty-twoother L2 learners read the same words marked by the other system (SystemB) that underlines long vowels and long consonants. As a control group, 20native Swedish speakers read the same words without any marking. Wemeasured and compared the temporal realizations of the six words by all thethree groups. System B readers realized Swedish phonological length moreclosely to the way that native speakers did, compared to System A readers.These results suggest that prompting both long vowels and long consonantscan be more effective than marking long and short vowels.