The sale of ready-to-eat salads has increased over the past years, yet little is known about consumer usage and the related safety of these products. This study evaluated the changes of microbiological quality of pre-washed spinach and mixed leafy vegetables during refrigeration storage. Microbial loads were determined by aerobic plate count (APC) and Enterobacteriaceae count (EC). The microbiological quality of pre-washed greens varied widely and deteriorated rapidly in a refrigerator. At “best if used by” date, twenty percent of samples had APC of more than 7.0 Log CFU/g and all samples had EC of more than 5.0 Log CFU/g. It is recommended that consumers purchase and eat pre-washed greens in their entirety as far in advance of the “best if used by” date as possible.