Objective: The objective of the present work deals with the synthesis, characterization and evaluation of antimicrobial and antioxidant activity of N-phenylpropyl-3-substituted indoline-2-one derivatives.Methods: A series of new 3-hydroxy-3-(2-oxoethyl)-1-(3-phenylpropyl) indolin-2-one derivatives 3(a-l) and 3-(2-oxoethylidene)-1-(3-phenylpropyl) indolin-2-one derivatives 4(a-l) were synthesized by knoevenagel condensation of N-phenylpropyl-5-substituted indole-2,3-diones with various acetophenones analogues. The chemical structures of synthesized compounds were confirmed by IR, 1 HNMR and Mass spectroscopic and elemental data. These compounds were also screened for their in vitro antimicrobial and antioxidant activities.Results: Novel compounds 3-hydroxy-3-(2-oxoethyl)-1-(3-phenylpropyl) indolin-2-one derivatives 3(a-l) and 3-(2-oxoethylidene)-1-(3-phenylpropyl) indolin-2-one derivatives 4(a-l) were synthesised and characterized using spectral and analytical data. The results of antibacterial and antifungal and antioxidant activities showed that some of the synthesized compounds exhibited promising results. Conclusion:All the newly synthesized compounds were screened for antimicrobial activity by cup plate method and antioxidant activity by the DPPH method using Ciprofloxacin and Amphotericin B as standards against gram positive and gram negative bacteria and fungi respectively.