What is grave abuse of discretion?

Grave abuse of discretion is the capricious or whimsical exercise of judgment that effectively brings the acting entity outside the exercise of its proper jurisdiction.[1] The abuse of discretion must be grave, as when the power is exercised in an arbitrary or despotic manner by reason of passion or personal hostility, and the abuse must be so patent and gross so as to amount to an evasion of a positive duty or to a virtual refusal to perform the duty enjoined, or to act at all in contemplation of law, as to be equivalent to having acted without jurisdiction.[2] [1] Feliciano v. Villasin, G.R. No. 174929, June 27, 2008, 556 SCRA 348; Uy v. Office of the Ombudsman, G.R. Nos. 156399-400, June 27, 2008.

[2] Vergara v. Ombudsman, G.R. No. 174567, March 12, 2009, 580 SCRA 693; Nationwide Security and Allied Services, Inc. v. Court of Appeals, G.R. No. 155844, 14 July 2008.