Allende is a senator and the daughter of former president Salvador Allende, who was overthrown in 1973.
Isabel Allende, daughter of Chile's martyred leader Salvador Allende, said she has decided not to stand for her nation's presidency, just weeks after announcing she was mulling a run.
"After deep reflection, I have decided not to go forward" with a presidential campaign, Allende told the Mediabanco news agency on Friday.
Allende is a senator and the daughter of former president Salvador Allende, who was overthrown by late dictator Augusto Pinochet in a 1973 coup.
Isabel Allende -- the leading name from the left who was considering a presidential run -- is not to be confused with her distant relative of the same name who is a best-selling novelist.
Allende said she will focus her efforts on "ensuring unity within the Socialist Party" her late father founded decades ago, alongside other leftist leaders.
The socialist party was in deep crisis after last week's local elections that gave conservatives with the Chile Vamos group a narrow victory over the ruling coalition of Bachelet's left-leaning New Majority.
General elections in 2017 will pick a successor for Chile's socialist President Michelle Bachelet, at a time when the left here is struggling.
Michelle Bachelet, the nation's first woman president, has been besieged by a corruption scandal involving her son and is struggling to deliver on the reform agenda that got her elected by a landslide in 2013.
She served a first term from 2006 to 2010, and -- constitutionally barred from immediate re-election -- returned in 2014.