1 Peso 1978 (Morelos, Cupronickel): Value Guide

If you inherited or found a Mexican 1 peso coin dated 1978, here is the honest answer: in circulated condition it is worth about face value, roughly 0.10 to 0.50 USD to a collector. A pristine, uncirculated example might reach 2 to 5 USD, but this is a very common coin, not a rarity.

This is one of the coins people most often ask us about because it looks old and heavy. It is not silver, and it is not scarce. Millions were struck. Below is what it actually is, what drives its value, and how to check yours before you sell.

What this coin is

The 1978 one peso is a large cupronickel coin (a copper-nickel alloy, no precious metal). It was part of Mexico's older peso currency, before the 1993 monetary reform that removed three zeros from the peso.

• Denomination: 1 peso
• Year: 1978
• Metal: Cupronickel (no silver, no gold)
• Weight: 8.97 grams
• Diameter: 29 millimeters
• Edge: Reeded (grooved)
• Mint mark: "Mo" for the Casa de Moneda de México (Mexico City Mint)

Front (obverse): The Mexican national coat of arms (an eagle on a cactus, devouring a serpent) with the legend "ESTADOS UNIDOS MEXICANOS."

Back (reverse): The portrait of José María Morelos, a leader of Mexican independence, along with the face value and the date "1978."

What it is actually worth in USD

The metal has no melt premium: cupronickel is worth almost nothing per coin. So value comes entirely from condition and collector demand, and demand for this date is low because it is abundant.

These are collector figures, not guarantees. A worn 1978 peso pulled from a jar is a face-value coin. The only way this piece brings real money is a certified, top-grade example, and even then the ceiling is modest.

The myth to kill

A large, old-looking Mexican coin does not mean it is valuable. Age alone drives almost nothing in numismatics. Value comes from rarity (low mintage or few survivors), demand, grade, and precious-metal content. The 1978 peso fails on rarity and metal, so it stays a low-value coin regardless of how heavy or antique it feels.

If you are hoping for a real payday from old Mexican coins, the pieces that command serious money are the silver and gold ones: the Centenario gold 50 pesos and the Onza Libertad silver bullion series, among others. The cupronickel peso is not in that league.

Errors and varieties

Genuine mint errors (off-center strikes, die rotation, double strikes) can multiply the value of any coin, including this one. But be skeptical: most "errors" shared online are post-mint damage (dings, corrosion, scratches), not factory mistakes. If you think you have a real error, photograph both sides and the edge and post it in the Pesoteca forum so the community can check it.

How to check what yours is worth

1. Grade it. Value swings entirely on condition here. Use our coin grading guide to judge wear and luster.
2. Verify it is genuine. Weigh it (should be 8.97 grams) and measure the diameter (29 millimeters) with a jeweler's scale and a caliper. Fakes usually show wrong weight, wrong size, flat relief, or off color.
3. Photograph it. Clear shots of the front, back, and edge under good light.
4. Get a second opinion before selling anything you think is unusual.

Where to sell it

For a common circulated coin, honestly, it is not worth much effort. If you have an uncirculated or possibly error example, sell through a verified dealer from the Pesoteca shop directory, who can appraise it on the spot, or list it in the Pesoteca buy-and-sell forum among collectors. Check the price range on this page before you accept any offer, and do not dump it to the first bidder on social media.

Have a jar of old Mexican coins and no idea which ones matter? Post your best photos in the forum and we will help you sort the face-value pieces from anything actually worth grading.

The circulating Mexican peso coins of the second half of the 20th century were struck in alloys that changed according to the cost of metals and inflationary processes: .720 silver in the $1, $5, $10, $25 denominations during the 1940s-50s; cupronickel from the 1970s; aluminum bronze and stainless steel in the 1980s; pieces with figures (Hidalgo, Cuauhtémoc, Juárez, Madero) in the late 1980s just before the transition to Nuevos Pesos in 1992. 1978 corresponds to the period when this variant was in circulation.