Still quite youthful when instructed by Apollo's oracle to avenge Agamemnon's murder, Orestes displays a level of immaturity that renders the ultimate revenge—the serious matter of matricide—morally ambiguous. His initial uneasiness about lying about his own death suggests a certain level of childish superstition, and his lie of choice—that he was killed in a chariot race—reflects the naiveté of both youth and wealth. His desire to avenge his father's death is not motivated by intense emotion or the principles of honor or justice. Orestes acts as he does because he has been so instructed by the oracle of Apollo.

Orestes's inexperience reveals itself on several occasions. When at first he hears Electra crying within the house, he expresses a desire to greet her immediately, already demonstrating a tendency to wander from the task at hand, which, as the Old Man reminds him, is to set the plan for revenge in motion. When he finally does meet Electra, he is unable to conceal his identity from her for long. He jeopardizes the secrecy of his plan by letting her know who he is, for which the Old Man scolds him. Once he has embarked on the actual act of revenge, however, Orestes's character does gain a level of maturity. Although still principally motivated by Apollo's instructions—insisting that the revenge is only as "good" as Apollo's oracle was "good"—he demonstrates an understanding of the justice at stake. He takes Aegisthus to kill him in the exact spot where Aegisthus murdered Agamemnon. Orestes' seeming maturation as the revenge unfolds compensates, in a sense, for Electra's increasing irrationality, but his initial immaturity and the cold source of his motivation make the audience shudder at the play's final outcome, wondering if what has happened is right.