Jakarta is one of the largest Cities in Indonesia where almost every year get flooding. Of course, flooding brings very bad impact for all human life aspect, which one is the incidence of various post-flood diseases. Environment changes caused by flood will increase the spreading of leptospirosis (rat urine disease). This is happen because of animal urine infected by leptospira germs are carryout by water pond and contaminate house environment. Leptospirosis problem in DKI Jakarta was always occurred in same area caused by bad environment factors, bad behavior, or individual characteristic influence. The research objective was to find out the impact of environment factor and individual characteristic on leptospirosis cases in Jakarta year 2003-2005. The study designed was case control study. Data are base on secondary data from Training and Education Division of Tarakan District Hospital, Jakarta and also with developed questioner for data collection. Subject cases were 190 people, whereas positive leptospirosis as cases group and negative leptospirosis respondent as control group, with 1:1 comparison. There ware significant relationship between environmental condition: house condition and settlement (OR=3,96), SPAL (OR=1,98), and characteristic individual: social economy condition (OR=1,93), knowledge (OR=17,6), and education (OR= 2,41). Multi variable analysis conclude that there are four dominant factors that affect leptospirosis which are environmental factors such as water supply (OR=4.5), house component and settlement (OR=8.2), individual characteristic: such as education (OR=3.7), knowledge (OR=33.1) related with leptospirosis cases in Jakarta year 2003-2005.