Background: Thin gingival phenotype is associated with increased susceptibility to gingival recession, soft-tissue instability, and compromised esthetic outcomes. The present study evaluated the effectiveness of microneedling (MN) with and without concentrated platelet-rich fibrin (C-PRF) for gingival phenotype modification. Methods: This prospective split-mouth comparative clinical study included 42 sites, with 21 sites each in the group A and group B. Ground A sites received MN with adjunctive C-PRF, whereas Group B sites received MN alone. Gingival thickness (GT) and keratinized tissue width (KTW) were assessed at baseline, 3 months, and 6 months. Postoperative pain was assessed using a visual analogue scale (VAS). Patient-level mean values were used for statistical analysis. Results: Both groups showed significant improvement in GT and KTW from baseline to follow-up. Group A demonstrated significantly greater GT than Group B at 3 and 6 months (P <0.05). Intergroup differences in KTW were not statistically significant. Pain scores decreased progressively in both groups without significant intergroup differences. Conclusion: Adjunctive use of C-PRF with microneedling resulted in superior improvement in gingival thickness and may represent an effective minimally invasive option for gingival phenotype enhancement.