This chapter deals with the articulatory and acoustic correlates of contrastive focus in French, in children and adults. Ten speakers (three 4-year-old, three 8-year-old children, and four adult males and females) were recorded while producing repetitions of the [baba] sequence in two prosodic contexts: in neutral condition and under contrastive focus. The opening (from the consonant into the vowel) lip gestures were video-recorded and monitored using the ICP tracking system. Lip area and its first derivative were described under both prosodic conditions, in the first and second [ba] syllables. Analyses of formant frequencies and RMS amplitude were also carried out on the acoustic signal. Results show that the effect of contrastive focus on articulatory measurements is smaller for children compared to adults. Results are discussed with respect to motor control development during childhood.