Background: This study aims to report the rate of biceps-related complications after LHB tenotomy, investigating related risk factors and their influence on the outcome. The hypothesis is that these complications have a limited clinical influence. Methods: A single-center prospective observational study was performed between 2015 and 2017 on consecutive patients who underwent RCR associated with LHB tenotomy. Patients were clinically and radiologically evaluated preoperatively, at six months and one year, and screened for postoperative popeye deformity, cramps, and bicipital discomfort. Each complication was analyzed for the following risk factors: age, sex, body mass index (BMI), dominant arm, manual work, tear patterns, and tendon healing. Finally, the clinical outcome was compared between patients with and without complications. Results: 207 patients were analyzed. Cramps, popeye deformity, and discomfort, were respectively, present in 16 (7.7%), 38 (18.4%) and 52 (25.1%) cases at six months and 17 (8.2%), 18 (8.7%) and 24 (11.6%) cases at one year. Cramps were associated with lower age (p = 0.0005), higher BMI (p = 0.0251), single tendon tear (p = 0.0168), manual work (p = 0.0086) at six months and manual work (p = 0.0345) at one year. Popeye deformity was associated with male sex at six months (p < 0.0001). Discomfort was associated with lower age (p = 0.0065), manual work (p = 0.0099), popeye deformity (p = 0.0240) at six months and manual work (p = 0.0200), single tendon tear (p = 0.0370), popeye deformity (p = 0.0033) at one year. Patients without complications showed a significant higher Constant score, pain and subjective shoulder value (SSV) (75.3 vs. 70.4, p = 0.00252; 0.9 vs. 1.9, p < 0.00001; 80.2 vs. 76.4; p = 0.00124) at six months and pain and SSV (0.6 vs. 2.0; p = 0.00044; 91.1 vs. 77.8; p ≤ 0.00001) at one year. Conclusions: Younger age, male sex, higher BMI, manual work, and single tendon tears are risk factors associated with the development of biceps-related symptoms during the first year after tenotomy in association with rotator cuff repair. Nevertheless, the clinical influence of these symptoms on shoulder outcomes is limited.