Twenty pesos coins (1917-1990)
Gold
KM-479 $20 1920 (Stack’s-Bowers NYINC auction 15 January 2022, lot 2331)
These were 90% gold and 10% copper, weighed 16.666 g with a diameter of 27.5 mm.
| Year | Mintage | |
| 1917 | 852,000 | |
| 1918 | 2,830,500 | |
| 1919 | 1,093,500 | |
| 1920 | 462,198 | 20 over 10 |
| 1921 | 921,500 | 21 over 11 |
| 1959 Restrike | 1,158,414 |
KM-478 1920 $20 20 over 10
KM-479 $20 1921 21 over 11 (Stack’s-Bowers auction 26 August 2025, lot 41453)
Silver
Type 1 - (Mayan culture)
KM-486
These were composed of 75% copper and 25% nickel. They had a diameter of 32 mm and weight of 15,14 g. Mintage was
| Year | Mintage | |
| 1980 | 84,900,000 | |
| 1981 | 250,573,396 | |
| 1982 | 236,892,000 | |
| 1984 | 55,000,000 |
Type 2 - (Victoria)
KM-508 1985 $20
These had a composition of 92% copper, 6% aluminum and 2% nickel, diameter of 21 mm and weight of 5.86 g.
| Year | Mintage | |
| 1985 | 25,000,000 | wide date, open 5: narrow date, open 5: wide date, closed 5 |
| 1986 | 10,000,000 | |
| 1988 | 355,200,000 | closed 8, open 8 |
| 1989 | 289,100,000 | |
| 1990 | 126, 550,000 | double-die reverse |
KM-508 $20 1985 doubled die reverse (DDR)
As many collectors of Mexico know, the Mexico City Mint was not of the highest quality and standards during the 1970s and 1980s, therefore quite a few errors and varieties can be easily found on coins dated from this period.