Short answer. Yes. Under Article 13 of the Revised Penal Code, that the offender had no intention to commit so grave a wrong as the one actually caused is a mitigating circumstance. It does not erase your criminal liability, but it can lower the penalty the court imposes.
What the law says
That the offender had no intention to commit so grave a wrong as that committed.
Revised Penal Code, Article 13 — Mitigating Circumstances. Read the full provision →
What 'no intention to commit so grave a wrong' means
The Code lists among the mitigating circumstances that the offender had no intention to commit so grave a wrong as that committed. Lawyers call this praeter intentionem. It applies where you did mean to do something wrong, but the harm that resulted was far graver than what you had in mind — for example, a single blow meant only to hurt that unexpectedly kills. The circumstance looks at the gap between the injury you intended and the injury that actually occurred. It does not apply where the grave harm you caused matches what you plainly set out to do.
It reduces the penalty, it does not remove liability
A mitigating circumstance is not a defence that clears you. You remain criminally liable for the felony; what changes is the penalty. Under the Code's rules on graduating penalties, a mitigating circumstance with no aggravating circumstance to offset it pushes the court toward the lower range of the penalty fixed for the crime. So the honest absence of intent to cause such serious harm is weighed in your favour at sentencing — it can shorten the punishment, but it will not by itself turn a conviction into an acquittal.
How intent is judged
Because this circumstance turns on your state of mind, courts do not simply take your word for it. Intention is inferred from the facts — the weapon or means used, the part of the body struck, the force applied, and the relationship between the act and the result. A notable disproportion between the means you employed and the death or serious injury that followed is what supports the claim. Where the natural and expected consequence of your act was exactly the grave harm that occurred, the circumstance will not be appreciated in your favour.
A note on the age-based mitigations
Article 13 also lists youth and old age as mitigating, and points a minor offender to a separate, older procedure. That part no longer states current law. Republic Act No. 9344 (2006), as amended by Republic Act No. 10630 (2013), now governs children in conflict with the law: a child fifteen years old or under is exempt from criminal liability, and a child above fifteen but below eighteen is exempt unless he acted with discernment. The old juvenile procedure the text refers to has been replaced by intervention and diversion. Read the age provisions subject to that Act.