Short answer. Yes. Section 31 makes deportation an additional penalty for a convicted alien. After serving the sentence, the foreigner is deported immediately without further proceedings. It is imposed on top of the penalty for the offence itself, and follows automatically once the sentence has been served.
What the law says
any alien who violates such provisions of this Act shall, after service of sentence, be deported immediately without further proceedings
RA 9165, Section 31 — Deportation Of Alien Offenders. Read the full provision →
Deportation is layered on top of the sentence
Section 31 is titled an additional penalty if the offender is an alien, and that framing is the key to it. The deportation does not replace the imprisonment or fine for the drug offence — it is imposed in addition to the penalties prescribed in the unlawful act committed. So a convicted foreigner first serves the sentence for the offence in full, and only then does the deportation consequence attach. It is a second, immigration-side penalty riding on top of the criminal one, not an alternative to it.
'Without further proceedings' is the striking part
The section provides that the alien shall, after service of sentence, be deported immediately without further proceedings. Ordinarily deportation is its own administrative process. Here the conviction and completed sentence are treated as sufficient, so the statute dispenses with a separate deportation case. That is what makes this consequence so difficult to avoid once a conviction stands: the usual avenue of contesting the deportation on its own footing is closed off by the words 'without further proceedings'.
The 'unless the penalty is death' exception
The text carves out one situation — it does not apply where the penalty is death, since a deported corpse is a contradiction. In practice that carve-out is now empty. Republic Act No. 9346 (2006) prohibited the imposition of the death penalty in the Philippines, so no offender can actually receive it. The result is that the deportation rule reaches every convicted alien who serves a sentence, because the one exception the section reserved can no longer arise. Older copies of the law still print the exception as though it were live.
Why timing and the underlying case matter most
Because the deportation hangs entirely on the conviction, the real contest is the criminal case itself, not the deportation that follows it. For a foreign national and their family, that makes the defence of the underlying charge — and any appeal — the decisive stage, since a conviction carries the immigration consequence almost mechanically. Anyone in this situation should get advice that treats the criminal and immigration exposure together from the outset, rather than waiting until the sentence is served and the deportation is already at the door.