The usual practice for eliminating biocolonization from stone statues in outdoor conditions has been the application of a biocide and subsequent cleaning. However, the cleaned condition is a transient state, and recolonization is inevitable. The recolonization rates can vary significantly as a function of the local and regional environmental conditions, and the respective patterns may exhibit strong variations at the microscale of the object. Given the variable time required for recolonization, the present study was undertaken over several years to collect data that although particularly relevant to the substrate considered and its environment, could shed some light as to which measures were the most effective in eliminating and preventing biocolonization. The paper focuses on the evaluation of various treatments applied in the past to the ornamental marble statues in the gardens of the National Palace of Queluz, Portugal.