A sensitive and accurate stability-indicating spectrofluorimetric method was created and validated for the determination of Cefdinir (CEF), a third-generation cephalosporin drug, via its acid and alkali-induced degradation products. The drug was determined via its acid-induced degradation products at 408 nm using an excitation wavelength of 292 nm, and via its alkali-induced degradation products at 458 nm after excitation at 330 nm. Linearity was achieved in the ranges 0.7—7.0 and 0.03-0.30 µg/mL for the acid-induced and alkali-induced degradation products, respectively. The investigation of degradation pathways was achieved using IR and LC/MS/MS. The technique was also validated by the International Conference on Harmonization Guidelines. The proposed technique was effectively implemented with excellent accuracy and precision to determine CEF in bulk powder and pharmaceutical dosage forms. The final results obtained by the application of the spectrofluorimetric method excellently agreed with the reported HPLC method.