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The Potters, who have finished ninth for the past three seasons, were beaten 4-1 by Crystal Palace on Sunday and are bottom of the table after five games.
"We have ambitions this season and if this run continues any longer we won't be able to achieve them," Hughes said.
"We need to turn this round very quickly. We haven't got going yet."
He added: "We've been ninth in the last three years, and we spoke about being better than that.
"Collectively we need to be better. We can't keep conceding easy goals like the first two."
Stoke failed to win any of their first six games last season but then won five of their next seven.
The former Wales boss was backed by his Palace counterpart Alan Pardew.
Some Eagles fans chanted "you're getting sacked in the morning" at Hughes, something Pardew felt was unjust.
"This is an experienced manager with very, very good players," Pardew said.
"Mark will deal with that. I have no concerns for him because he's terrific. He's having a bit of downtime, but he'll be fine. I have heard those chants against me. I don't think it's right."
Stoke City boss Mark Hughes says his team's poor start in the Premier League could see them miss out on their pre-season targets.