Objective: To review the current literature, and to evaluate the occurrence, severity, and duration of tooth sensitivity during and after vital tooth bleaching as well as to identify possible sources and risk factors of bleaching sensitivity (BS). The inclusive analysis should allow the clinician to get an overview about today's evidence based results concerning BS. Search Strategy: The search included Cochrane Central Register of Controlled Trials, Ebsco, Embase, PubMed, and Scopus from February 1991 to February 2015. Studies published in English and German were considered. Selection Criteria: Randomized controlled trials including placebo or control groups, with statistical analysis of BS interventions, and with a study sample size of at least 30 participants at baseline were selected. Data Collection and Analysis: Screening of titles and abstracts, data extraction, and quality assessment of full texts were undertaken. Results: A total of 136 articles were identified, with 18 papers meeting the inclusion criteria and presenting data that could be used in the analysis. Included trials provided some details on occurrence, severity, or duration of BS, but papers did not focus solely on BS. The majority of the studies were judged to be at a high risk of bias according to their study design. Investigation methods and outcomes concerning severity of BS and duration varied significantly. Evidence-based explanations for BS could not be found. Conclusion: BS still remains an unsolved phenomenon that needs further follow-up with high-quality studies following the well-accepted CONSORT guidelines. Keywords: bleaching sensitivity, carbamide peroxide, hydrogen peroxide, risk factors/predictors, therapeutic aspects, tooth sensitivity, vital tooth bleaching