Supercritical fluid extraction (SFE) of uranium and thorium from solid matrices was carried out employing Co-2. Direct dissolution and extraction of oxides of uranium viz. UO2 and U3O8 was performed. UO2 and U3O8 powders (0.02-0.05 g) along with 2 ml of TBP-HNO3 complex were taken in extraction vessel and CO2 was fed until 150 atm. pressure and 60 degrees C temperature were achievable. After 20 min uranium extraction was performed by continuously flowing supercritical fluid mixture of CO2 and 10% TBP for 45 min. Uranium extraction efficiency for U3O8, was 97.05 +/- 3.73% and for UO2 was 98.07 +/- 4.76%. For SFE of thorium from tissue paper matrix, TBP and TOPO (0.2 M in CCl4) were investigated as complexing agents. In online complexation mode, mixture of CO2 and 10% complexing agent was fed to the extraction vessel. The vessel was maintained at pressure of 200 atm. and temperature of 60 degrees C for 20 min followed by 20 min of extraction. TOPO was found to be more effective than TBP as extraction efficiencies with TBP and TOPO were 52.51 +/- 7.54% and 65.65 +/- 7.78% respectively. The efficiency was found to improve with a combination of 1: 1 volume ratio of TBP and TOPO (0.2 M in CCl4). No further improvement was observed with TOPO plus 10% methanol. In in-situ mode higher efficiency i.e. 89.83 +/- 7.04% was observed with employing TOPO as a complexing agent. Uranium and thorium were determined spectrophotometrically employing arsenazo III metal indicator for color development.