Here, a TLC–densitometric assay was developed and optimised for monitoring of residual caffeine and EGCG content in GT extracts. The assay conditions were optimised to achieve good resolution between bands corresponding to EGCG, caffeine and GA. Optimisation of the separation conditions and various instrumental settings were first carried out. Previously reported developing systems of different composition and ratios were tried, such as chloroform:acetone:methanol (30:30:30 v/v/v) (Verma & Kumar, 2010), ethyl acetate:methanol:water (100:13.5:10 v/v/v) (Mohamm, 2009), water:acetonitrile:methanol:acetic acid (79.5:18:2:0.5 v/v/v/v), ethyl acetate:formic acid:acetic acid:water (100:11:11:26, v/v/v/v), chloroform:ethyl acetate:formic acid (5:4:1 v/v/v) (Malbasa et al., 2004) and dichloromethane:acetone:formic acid (5:10:1 v/v/v and 10:5:1 v/v/v) (Zhao et al., 2009). Replacement of formic acid by ammonia has also been tried, in order to reach the optimum composition for the TLC system. Results were evaluated with respect to efficiency of separation and the shape of separated bands.