Chiara Bordi, 18, who lost her leg in a bike accident when she was 13, was chosen as one of three finalists in the competition that was won by Carlotta Maggiorana.
The last few days have been marked by spats between Bordi's detractors and her supporters.
“I'm missing a leg, but you're missing a heart and brain,” Bordi, from the central Tarquinia province, wrote on her Facebook page after she was accused of being in the competition “just because you're crippled”.
“There are all sorts of frustrations and dissatisfactions behind this nastiness,” Bordi wrote.
“I'm not interested in winning, but showing the world that life is still beautiful [even] when reborn after a dramatic event.”
Chiara Bordi competing. Photo: Miss Italia/Facebook