Introduction Atopic dermatitis (AD) affects multiple areas of the body, some of which may be more refractory to treatment. We evaluated improvements in the Eczema Area and Severity Index (EASI) by body region and clinical signs for each body region in lebrikizumab-treated patients with moderate-to-severe AD. Methods ADvocate 1 and ADvocate 2 compared lebrikizumab 250 mg as monotherapy every 2 weeks versus placebo for 16 weeks. Efficacy measures included EASI, which rates the extent and severity of four clinical signs (erythema, edema/papulation, excoriation, lichenification) in four body regions (head/neck, upper extremities, trunk, lower extremities). Analyses are post hoc. Results Mean baseline EASI, body region EASI subscores, and the severity of clinical signs were consistent across both studies (EASI ranging from 16.0 to 72.0). At week 16 in both studies, patients treated with lebrikizumab showed significantly greater percent improvement in EASI across all body regions versus placebo (p ≤ 0.001), with improvements as early as week 2. In ADvocate 1, all clinical signs significantly improved across all body regions at week 16 with lebrikizumab (51.4–71.6% improvement) versus placebo (23.1–43.5%, p ≤ 0.001), with significant improvements as early as week 2 for all signs. Significant improvements for all clinical signs at week 16 were also seen in ADvocate 2 for lebrikizumab (53.5–75.6%) versus placebo (28.5–41.2%, p ≤ 0.001) and as early as week 2 for all body regions and signs except head/neck erythema and lower extremity erythema, edema/papulation, and lichenification, which showed significant improvement by week 4. Conclusions Lebrikizumab as monotherapy consistently and rapidly reduced the extent of involvement and severity of AD in all EASI clinical signs and body regions, including the head and neck region and clinical sign of lichenification, compared with placebo.