Natural attenuation is increasing in use as a low cost means of remediating contaminated soil and groundwater. Modelling of contaminant migration plays a key role in evaluating natural attenuation as a remediation option and in ensuring that there will be no adverse impact on humans and the environment. During natural attenuation, the contamination must be characterized thoroughly and monitored through the process. In this paper, attenuation mechanisms for both organic and inorganic contaminants, use of models and protocols, role of monitoring and field case studies will be reviewed.