This paper aims to provide a systematic review of the literature on the associated factors with infant sleep-wake behaviour during the first 12 months of life, namely (1) the factors positively and negatively associated with sleep-wake behaviour and (2) the factors positively and negatively affected by sleep-wake behaviour. This systematic review was based on a standard protocol constructed according with the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) statement and included 146 papers. Two typologies of factors were found in the literature: factors positively and negatively associated with infant sleep-wake behaviour and effects of sleep-wake behaviour. Different factors were identified as being positively and negatively associated with the different sleep-wake behaviours and positively and negatively affected by the different sleep-wake behaviours during the first 12 months of life. Some inconsistent results could be explained by methodological differences between the studies.