Heavy metals speciation of Mexican Lake Chapala sediments was studied using sequential extraction to assess their mobility. Mineralogical constitution of sediments was studied by XRD. Results show Pb and Cr present in exchangeable and carbonate fractions indicating anthropogenic origin. Risk Assessment Code indicates low risk of pollution for water column. XRD results indicate mineralogy of Lake Chapala sediments present spatial variation. Presence of Pb and Cr in exchangeable and carbonate fractions suggests heavy metals pollution control not effective by corresponding authorities.