Short answer. Sometimes. A waiver can be valid if the seller was in good faith, but the Civil Code voids any stipulation exempting the seller from answering for eviction where he acted in bad faith. A seller who knew of the defect in his title cannot contract his way out of it.
What the law says
Any stipulation exempting the vendor from the obligation to answer for eviction shall be void, if he acted in bad faith.
Civil Code, Article 1553 — Void Waiver in Bad Faith. Read the full provision →
What the warranty is protecting
Eviction happens when a buyer is deprived, by a final court judgment and on a right existing before the sale, of the whole or part of what he bought. Someone else turns out to be the owner, or holds a claim that defeats the buyer's. The law makes the seller answer for that outcome because the seller is the one who represented that he had something to sell. Buyers usually meet this warranty only after the worst has already happened — a case filed by a stranger, a title that will not transfer, an adverse claim annotated on the certificate. The waiver clause in the deed is then the first thing both sides reach for.
Good faith decides whether the clause survives
The article draws one clean line. A waiver executed by a seller who genuinely believed his title was sound can operate — the parties are free to allocate a risk neither of them knew about. A waiver signed by a seller who knew his title was defective, or who knew of the outstanding claim and said nothing, is void. Bad faith is not a technicality here; it is the whole test. The clause is struck down not because waivers are disfavoured but because a person cannot use a contract to secure the benefit of his own concealment.
What a valid waiver actually gets the seller
Even where the waiver stands, it does not always wipe the slate clean. The Civil Code distinguishes between a buyer who merely renounces the warranty in general terms and one who knowingly assumed the specific risk of eviction. Only the second — a buyer who understood the danger and accepted it — leaves the seller fully discharged. In the first situation the seller may still have to return the value of the thing at the time of eviction. So a boilerplate "the buyer waives all warranties" line does much less for the seller than he imagines, and it does nothing at all if he was hiding something.
Practical points for both sides
For a buyer, the answer is not to argue about the clause afterwards but to look before signing: verify the certificate of title with the registry, check for annotations, adverse claims and pending cases, and ask who is actually in possession. For a seller, disclosure is protection — a risk that is written into the deed and expressly accepted is far stronger than a blanket waiver. Note that this provision governs eviction, not physical faults in the thing, which fall under a separate warranty with its own rules and much shorter deadlines. Whether a particular clause holds up turns on what each party knew when the deed was signed, and is worth reviewing with counsel before a case is filed.