Various S-methylphenyl substituted acridine-1,8-dione series (4a–i) were synthesized through a one-pot cascade synthetic approach involving the reaction of 4-(methylthio)benzaldehyde and dimedone with a variety of amines as nitrogen source under reflux in ethanol. All the synthesized derivatives were characterized by using spectroscopic methods. In vitro evaluations of anti-inflammatory and antidiabetic efficacies of all the synthesized compounds were investigated. The anti-inflammatory results infer that the compounds 4c and 4d are showing excellent activity with an inhibition percentage of 80.58 ± 0.42, 81.72 ± 1.72 by membrane stabilization and 77.72 ± 0.76, 78.76 ± 0.81 by albumin denaturation methods, which is comparable with the standard diclofenac at a concentration of 100 μg/ml. Further, the antidiabetic assay revealed the moderate activity for the synthesized compounds at a concentration of 100 μg/ml with respect to their standard drug, acarbose. © 2017 John Wiley & Sons A/S