Recurrent low back pain (recurrent LBP) is a common condition, however, it is unclear if uniform definitions are used in studies investigating the prevalence and management of this condition. The aim of this systematic review was to identify how recurrent LBP is defined in the literature. A literature search was performed on MEDLINE, EMBASE, CINAHL, AMED, and PEDro. Studies were considered eligible if they investigated a cohort of subjects with recurrent LBP or if they were measuring the prevalence of recurrent LBP. Two independent reviewers assessed inclusion of studies and extracted definitions of recurrent LBP. Forty-three studies met the inclusion criteria. The majority of studies (63%) gave an explicit definition of recurrent LBP; however, the definitions varied greatly and only three definitions for recurrent LBP were used by more than one study. The most common feature given as part of the definition was the frequency of previous episodes of low back pain. Only 8% (3/36) of studies used previously recommended definitions for recurrent LBP. Large variation exists in definitions of recurrent LBP used in the literature, making interpretation of prevalence rates and treatment outcomes very difficult. Achieving consensus among experts in this area is required.