Importance:Surgeons have varying opinions on the ideal cutaneous suture spacing for optimal cosmetic outcomes. To date, no studies concerning the effect of suture spacing on cosmetic outcomes exist in the literature. Objective:To compare outcomes and wound cosmesis achieved with running cutaneous sutures spaced 2 vs 5 mm apart. Design, Setting, and Participants:This randomized clinical trial was conducted at the University of California, Davis dermatology clinic from November 28, 2017, to June 15, 2018. Fifty-six patients 18 years or older with surgical fusiform wounds (from Mohs procedure or surgical excision) on the head or neck with assumed closure lengths of at least 3 cm were screened. Six patients were excluded, 50 patients were enrolled, and 48 patients were followed up. Interventions:Fifty surgical fusiform wounds were randomized to running cuticular closure with 2-mm spacing on half and 5-mm spacing on half. Main Outcomes and Measures:At 3 months, patients and 2 masked observers evaluated each scar using the Patient and Observer Scar Assessment Scale (POSAS). Results:A total of 50 patients (mean [SD] age, 71.1 [11.4] years; 43 [86%] male; 50 [100%] white) were enrolled in the study. The mean (SD) sum of the POSAS observer component scores was 10.7 (4.3) for the 2-mm interval side and 10.8 (3.5) for the 5-mm side at 3 months (P = .77). No statistically significant difference was found in the mean (SD) sum of the patient component for the POSAS score between the 2-mm interval side (10.2 [4.7]) and the 5-mm interval side (11.5 [6.4]) at 3 months (P = .24). No statistically significant difference was observed in mean (SD) scar width between the 2-mm side (0.9 [0.6] mm) and the 5-mm side (0.8 [0.4] mm; P = .15). Conclusions and Relevance:No statistically significant difference in wound cosmesis or total complications were noted between running cuticular sutures spaced 2 vs 5 mm apart. Both suturing techniques resulted in similar cosmetic outcomes and complication rates. Surgeons may want to consider whether the extra time involved in placing very closely spaced cuticular sutures is worthwhile. Trial Registration:ClinicalTrials.gov identifier: NCT03330041.