Mexican 5 Pesos 1985 (Brass): What It's Really Worth

If you inherited or found a Mexican 5 pesos dated 1985, here is the honest answer: it is worth about 15 US cents circulated, and roughly 35 to 50 cents in uncirculated condition. This is a common brass coin, not silver, and not the rare piece some listings pretend it is. Below is exactly what you have and how to verify it.

Quick answer: is the 1985 5 pesos worth money?

No, not in any meaningful way. In 2026, catalogs place the small 5 pesos of 1985 (KM#502) near face value: around 0.15 USD for a worn example and 0.35 to 0.50 USD for one that never circulated. Mexico's central bank (Banxico) struck 30 million pieces dated 1985 alone, and the same design kept being minted through 1988, so surviving coins number in the hundreds of millions. There is no shortage.

Any online listing claiming this coin is worth hundreds of thousands of pesos is either a mistake or a scam. The real figures are the ones above.

What you actually have

The 1985 5 pesos is a small, light brass coin. Here are the exact specifications, which matter for both identification and authentication:

The alloy is sometimes called aluminum-bronze, which is why people occasionally think it is something more valuable. It is not. There is no silver and no gold in this coin, so it has zero precious-metal value. Its worth is entirely collector-driven, and demand for a common brass piece is low.

The Quetzalcóatl mix-up (very common)

If someone told you your 1985 5 pesos shows the feathered-serpent god Quetzalcóatl on the back, they are describing a different coin. This small brass 5 pesos (KM#502) carries only the numeral 5, the peso sign, and the year. No portrait.

The Quetzalcóatl head appears on the earlier, larger and heavier 5 pesos struck in copper-nickel (KM#485, 10.25 grams). That is a bigger, thicker coin. If yours weighs 3.1 grams and measures 17 mm, you have the small brass type with no portrait. Weigh it if you are unsure.

Why this coin exists

The 1985 5 pesos belongs to the last stretch of what collectors call the "old pesos," before Mexico's 1993 monetary reform removed three zeros and introduced the Nuevo Peso. By the mid-1980s, inflation had shrunk the buying power of small coins, and 5 pesos already circulated as pocket change of little value. That context is exactly why so many were made and why so few are worth keeping today.

Where the small value lives

One place a collector will pay a bit more: fully uncirculated examples with original mint luster and a sharp strike. Even then you are talking cents, not dollars. This coin fits naturally into a date-run of the brass 5 pesos series, or a set documenting Mexican circulating coinage before the Nuevos Pesos reform. It is an accessible, easy-to-find piece, which is precisely why it stays cheap.

What about the famous error?

There is no documented valuable error for 1985. The known case is the 1987 issue, when the Mint used a defective alloy and destroyed nearly the entire run. That failed-batch story belongs to 1987, not 1985. Do not let a seller attach the 1987 story to a 1985 coin.

How to tell if yours is genuine

Authentication here is simple because the coin is common and low-value, so counterfeits are essentially nonexistent. Just confirm the specs:

• Weight: 3.1 grams
• Diameter: 17 mm
• Edge: reeded
• Obverse: National Coat of Arms with ESTADOS UNIDOS MEXICANOS
• Reverse: large 5, peso sign, year 1985, mint mark Mo

If the numbers line up, it is genuine. A cheap kitchen scale and a ruler settle it.

Where to sell it

Because of its low value, this coin rarely appears in serious auctions. Selling a single one is not worth the effort. If you want to buy a nice uncirculated example for a set, or you have a larger lot of old Mexican coins to move, the practical route is the Pesoteca directory of coin shops and buyers. For identifying other coins in your inheritance, our guide to Mexican coins that are actually worth money is a better place to start than any single common date.

Have a box of old Mexican coins and no idea which ones matter? Post clear photos of the whole lot in the Pesoteca forum and we will help you spot the ones worth setting aside from the ones worth a few cents.

Mexican circulating peso coins from the second half of the 20th century were struck in alloys that changed according to the cost of metals and inflationary pressures: .720 silver in the $1, $5, $10, $25 denominations during the 1940s-50s; cupronickel from the 1970s onward; aluminum bronze and stainless steel in the 1980s; pieces with historical figures (Hidalgo, Cuauhtémoc, Juárez, Madero) in the late 1980s just before the transition to Nuevos Pesos in 1992. 1985 corresponds to the period in which this variant was in circulation.