A synopsis of evidence on the impact of factors impeding or facilitating implementations of guideline-based CDSS used by physicians is absent from the scientific literature. This systematic literature review provides an integrated understanding of these factors, based on a socio-technical framework. Research on factors influencing CDSS implementations has mainly focused on human and technology factors and less on organizational factors. Future research within the field of guideline-based CDSS should focus on evaluating implementations through the use of socio-technical models.