Purpose: Most acoustic and articulatory studies on /l/ have focused on either duration, formant frequencies, or tongue shape during the constriction interval. Only a limited set of data exists for the transition characteristics of /l/ to and from surrounding vowels. The aim of this study was to examine second formant (F2) transition characteristics of /l/ produced by young children and adults. This was to better understand articulatory behaviors in the production of /l/ and potential clinical applications of these data to typical and delayed /l/ development. Method: Participants included 17 children with typically developing speech between the ages of 2 and 5 years, and 10 female adult speakers of Southern American English. Each subject produced single words containing pre- and postvocalic /l/ in two vowel contexts (/i, [near-close near-front unrounded vowel]/ and /[open-mid back rounded vowel], [open back unrounded vowel]/). F2 transitions, out of and into /l/ constriction intervals from the adjacent vowels, were analyzed for perceptually acceptable /l/ productions. The F2 transition extent, duration, and rate, as well as F2 loci data, were compared across age groups by vowel context for both pre- and postvocalic /l/. Results: F2 transitions of adults' /l/ showed a great similarity across and within speakers. Those of young children showed greater variability, but became increasingly similar to those of adults with age. The F2 loci data seemed consistent with greater coarticulation among children than adults. This conclusion, however, must be regarded as preliminary due to the possible influence of different vocal tract size across ages and variability in the data. Conclusions: The results suggest that adult patterns can serve as a reliable reference to which children's /l/ productions can be evaluated. The articulatory configurations associated with the /l/ constriction interval and the vocal tract movements into and out of that interval may provide insight into the underlying difficulties related to misarticulated /l/.