Objective: To ascertain whether low preoperational maximal urethral closure pressure (MUCP) affects the outcomes of single incision sling (SIS) procedures and changes MUCP values postsurgery. Material and methods: There were 112 (MUCP ≥ 40 cmH2O, n = 88; MUCP < 40 cmH2O, n = 24) consecutive women with urodynamic stress incontinence who had undergone SIS (MiniArc) procedures included in this study. The threshold of 40 cmH2O was used since it has been shown to be a significant risk factor for failed incontinence surgery. Clinical outcomes were assessed by the cough stress test, the 1-hour pad test, the Incontinence Impact Questionnaire-Short Form, the Urogenital Distress Inventory six-item questionnaire, the Sexual Questionnaire-SF, and postoperative changes in the urodynamic parameters. A comparison of the 1-year follow-up data is presented. Results: Three months postsurgery, a significant decrease was observed in the 1-hour pad test, from 20.6 g preoperatively to 0.73 g postoperatively (p < 0.001). The objective cure rate was 82.1% without any significant differences between the two groups (p = 0.202). At 3 months and 1 year after surgery, significantly decreasing Urogenital Distress Inventory six-item questionnaire and Incontinence Impact Questionnaire-Short Form, and increasing Sexual Questionnaire-SF scores were observed in both groups, without any significant differences between the two groups. No statistically significant difference in the subjective cured rate was noted between the two groups at the 3-month and 18.4 month follow-ups. The postoperative MUCP was significantly decreased in the MUCP ≥ 40 group (p < 0.05) while significantly increased in the MUCP < 40 group (p = 0.006). Conclusions: These results suggest that SIS is a safe and highly effective treatment for urodynamic stress incontinence even in women with low MUCP at a mean follow-up of 18.4 months. Evaluation of the outcomes with more subjects after a longer follow-up period is necessary.