Laboratory wastewater contains organic and inorganic compounds that are harmful to the environment when dispose without prior treatment. Beside of the high COD and BOD values, the laboratory wastewater also contains metals such as iron (Fe), zinc (Zn), copper (Cu), chromium (Cr), and lead (Pb) which categorizes as dangerous waste material and can pollute the groundwater. Although the quantity of wastewater produced by the laboratory is relatively small, it has a real impact on the environment around the laboratory. However, the wastewater has to treat properly before discharge into the environment. The aim of the research was to study the laboratory wastewater treatment by using Fenton's reagent with coagulation and adsorption pretreatment. In the pretreatment with coagulation, three types of coagulants are used, namely PAC (Poly Aluminum Chloride), ACH (Aluminum Chlorohydrate) and Aluminum Sulfate (AS) with their respective concentrations of 10-80 ppm. The highest percentage of average pollutant removal of 58.21% was found when applied 80 ppm of AS. The pretreatment was continued by adsorption with activated carbon and zeolite adsorbents within 60-120 minutes of mixing time. It was detected, the most optimum adsorbent was activated carbon with average pollutant removal of 50.22% within 1 hour of mixing time. Processing was extended by utilized Fenton's reagent using a variation of the molar ratio between 1:100-1:400. It was obtained that the best molar ratio to degrade the laboratory wastewater is 1:300 with an average removal of pollutant of 43.45%. As a result of laboratory wastewater treatment using combine Fenton's reagent and coagulation-adsorption pretreatment, an average pollutant removal of 90.81% was obtained. The final content of COD, BOD, TSS, as well as Cu and Pb metal has met the environmental quality standard.