Introduction: Inflammation is body’s immune response to harmful stimulus. Commonly used conventional antiinflammatory agents are Non-Steroidal Anti-inflammatory Drugs (NSAIDs). But on prolonged long-term use, it causes serious adverse events. So, the search towards natural agents which have anti-inflammatory property are increasing nowadays. Sinapis arvensis is an annual flowering plant which has proven multipurpose medicinal phytoconstituents. Aim: To evaluate in-vitro anti-inflammatory effects of flower extracts of Sinapis arvensis with diclofenac as standard. Materials and Methods: This in-vitro study assessed the laboratory based anti-inflammatory activity, performed using Bovine Serum Albumin (BSA) assay in December 2021 at Sree Balaji Medical College and Hospital, Chennai, Tamil Nadu, India. BSA at pH of 6.8 generated denatured proteins. The anti-inflammatory activity of the sample (flower extracts of Sinapis arvensis) and standard (Diclofenac) was assessed by adding to BSA and percentage of inhibition of denaturation were calculated using the formula based on the absorbance measured. Descriptive statistics was used for analysis of collected data. Results: The concentration-dependent inhibition of protein denaturation was observed for both Sinapis arvensis and Diclofenac. At 100 µg concentration, percentage of inhibition reached up to 81.8% and 100% for Sinapis arvensis and Diclofenac, respectively. Conclusion: The present study showed that flower extracts of Sinapis arvensis exhibited concentration dependent antiinflammatory property invitro which proves to be nearly equivalent with that of the standard Diclofenac.