The East Slavic languages have distinctive stress and no contrastive vowel length; the phonetic correlates of word stress are increased vowel duration, intensity and changes in vowel quality. But there are East Slavic dialects with an unusual type of word prosody: word stress is distinctive, yet the immediately pretonic vowel is as long as or longer than the vowel under stress, and there is a fixed tonal contour over the two syllables. I argue that the additional duration in the pretonic syllable is due to a type of stress-to-tone mapping in which a lexical high tone is assigned to the pretonic syllable. Variation across these and other closely related dialects reveals a typology of stress and tone mapping with increasing dependence on intrinsic vowel duration and sonority. The additional vowel length on neutralised/reduced vowels in the immediately pretonic position in some dialects raises questions about the relationship of vowel duration and vowel reduction in East Slavic. The prosody of these East Slavic dialects appears to be typologically unusual in having both lexical stress and non-contrastive tone, and in specifically not aligning high tone with stress.