One of the early signs of aging is loss of jawline contour. Not all cases require surgical intervention and soft-tissue augmentation with injectable fillers may restore the profile and youthful appearance of the jawline.To demonstrate the effectiveness and safety of calcium hydroxylapatite with lidocaine [CaHA (+); Radiesse® (+)] to improve the contour of jawline after deep (subdermal and/or supraperiosteal) injection.Healthy eligible patients with moderate or severe ratings on the Merz Jawline Assessment Scale (MJAS) were randomized 2:1 to treatment with CaHA (+) or to control. Patients in the control group remained untreated until week 12, then received delayed treatment. Touch-ups were allowed in both groups, and re-treatment was allowed in the treatment group only. Effectiveness was evaluated on the MJAS, patient and investigator Global Aesthetic Improvement Scales, and FACE-Q™ questionnaires. Adverse events were recorded over a 60-week period.Treatment response rate (≥1-point MJAS improvement) was 93/123 (75.6%) for the treatment group and 5/57 (8.8%) for the control/delayed-treatment group at week 12. The difference between response rates was statistically significant (P<0.0001), showing superiority of treatment over control. Satisfaction with aesthetic improvement was reported by patients and treating investigators throughout the study. A total of 76/113 (67.3%) patients who responded to treatment 12 weeks after initial injection also demonstrated persistent improvement 48 weeks after initial treatment. The study demonstrated a favorable safety profile, with no reported unexpected adverse events.CaHA (+) is a safe and effective treatment for improving the contour of the jawline. J Drugs Dermatol. 2021;20(11): 1231-1238. doi:10.36849/JDD.6442.