The microscopic agglutination test (MAT) is the gold standard for serological diagnosis of leptospirosis. This method uses panels of live Leptospira from recent isolates representing the circulating serovars from the area where the patient became infected. The patient’s serum is mixed with a suspension of live Standardized Leptospira in micro titer well plates at the dilution of 1:100 and incubating for 2 hr. at 30°C. The positive result are read a 50% agglutination under the dark-field microscope. A Two-fold dilution series of the patient’s serum positive were tested against the Standardized Leptospira for reporting final titer. Presumptive cases of leptospirosis are considered when a MAT titer of 1:100 or greater against one or more of the Leptospira serovars with a single serum sample are obtained. A four-fold rise or greater in MAT titer of the paired (acute versus convalescence) serum samples against one or more of the Leptospira serovars, can be use for diagnostic of current leptospirosis infection.