These two flags have one thing in common: the same color scheme(green, white, and red). They are also aligned in the same way. There is only one difference between them. The Mexican flag has an eagle attacking a snake as its logo.
According to both a webpage titled "Flag Symbols" and Houseofnames.com, the eagle represents God, Heaven, good, and the sun, while the snake represents evil.
The snake as a symbol of evil has precedent, especially in The Biblical book of Genesis. The snake, known also as a serpent, successfully tempted Adam and Eve to eat an apple from the Tree of Knowledge, against God's wishes, thus banishing both of them from the Garden of Eden.
The eagle as a symbol is also used in the United States. In fact, the bald eagle is the official bird of the United States.
Now as for the colors, the site three-musketeers.net states the following:
Green usually means "nature, the environment, good luck, youth, vigor, jealousy, envy, and misfortune".
White usually means "angels and gods, as the color reflects that which is sacred and pure".
Red usually means "strong emotions, or things of strong emotions rather than intellectual ideas. For example, red can symbolize excitement, energy, speed, strength, danger, passion, and aggression."
We must now compare that with what experts say about the colors of each flag.
According to the webpage called Flag Symbols,
* Green symbolizes Hope, the deep Aspiration to return to the unity of the being, who is torn between his different contradictory aspirations and to the union of the beings gathered under the same banner.
* White depicts Faith of the beings ready to undertake this return voyage, the total abandonment to the divine powers symbolizing unity and the trust without limits in Gods and oneself.
* Red means divine Love, the Love that supports us alongside the way towards the deep reality of our nature in which we are only one.
However, is it the same thing for the Italian flag? For green and white, yes, but red in the Italian flag actually means charity, according to The Italian Flag 101.
So there you have it, the Mexican and Italian flags, same colors, almost identical meanings.
"Flag symbols: Mexico, the eagle and the serpent-LOTUS". Lotus-At the Heart of Symbolism. Web. 10 Nov 2009. [http://users.skynet.be/lotus/flag/mexico0-en.htm]
"The Italian Flag 101." In Italy Online - Hotels in Italy, Villas in Italy, Lodgings in Italy, Traveling to Italy and Information about Italy. Web. 10 Nov. 2009. [http://www.initaly.com/gene/flag101.htm].
"The Story of the New York State Bird." New York State Bluebird Society Home page. Web. 10 Nov. 2009. [http://www.nysbs.org/nysbird.htm].
"Symbolism - eagle." Coats of Arms (Family Crests) & Surname Histories. Web. 10 Nov. 2009. [http://www.houseofnames.com/xq/asp/keyword.eagle/qx/symbolism_details.htm].
"Symbolism: Colors." Three-musketeers.net -- Fun Stuff For the Web. Web. 10 Nov. 2009. [http://www.three-musketeers.net/mike/colors.html].