Eyebrows were raised when the Foxes splashed out a reported £8million this summer to bring the Argentinian to the King Power Stadium from Brighton - a hefty sum for a 28-year-old yet to play in the top flight.
But Ulloa has silenced the doubters with three goals in his first four Barclays Premier League games, including the only goal as Leicester secured their first win of the season at Stoke on Saturday.
The former Almeria forward has also impressed with his work-rate, and he sees his primary responsibility as doing whatever he can to help the team.
He said of his flying start: "It's good for me but it's much better for the team
We've got the first win
I'm happy
I'm not surprised because I work all the time.
"I don't think about the money
When you think about that, it's difficult
I like playing for Leicester, I like playing with my team-mates, and I want to help.
"I enjoy every game and every training session
Yes the club paid this money, but I don't think it's more pressure
It's a good pressure."
Ulloa joined Brighton from Spanish side Almeria in January 2013 and scored 23 goals in 50 Championship appearances.
He has taken the latest step up in his stride, and said: " It's different because in the Premier League there's more quality and more intensity than in the Championship
But it's a little difference, not a big difference
It's a good experience for me
I'm enjoying everything."
Ulloa has scored all but one of Leicester's Premier League goals so far, and earned praise from his strike partner David Nugent
"He's on fire," said the one-time England man
"He's come in, big-money signing, and he's producing the goals on his own at the moment
I'm trying to get up there to support him but he's getting the goals and he fully deserves it."
It has been an impressive start to the season for the Championship winners, who have taken five points from clashes against Everton, Arsenal, Chelsea and Stoke, setting them up nicely for next weekend's meeting with Manchester United
"I think it will be massive," Nugent said of their first victory
"Going forward it's always nice to get the first one, especially away from home as well against a team that just beat Manchester City
Five points out of the first 12, no one expected it, so we're doing well do far
"The start we had was pretty difficult
To pick up points on the road is important because it's probably the home form that will keep us up but we're all encouraged by the start we've made."
At half-time at the Britannia Stadium, a Leicester win looked an unlikely outcome after Stoke had dominated the first 45 minutes.
But the hosts did not take their chances and were made to pay, with Leicester improving noticeably after Esteban Cambiasso and Danny Drinkwater came on for the second half.
Former Argentina international Cambiasso, 34, spent the last 10 years with Inter Milan before his release at the end of last season.
"He's a quality player," said Nugent
"He can see passes before he plays them
His experience will do us the world of good and he showed that in the second half
"He's a great talker on the pitch, his English is really good
We didn't expect that
He's a quality man as well."
Oussama Assaidi felt Stoke were very unfortunate to come away with nothing
"We dominated the game but we didn't score the chances," he said
"If they get one, they can make it
I think we could have easily won this game, but football's like that
"Everyone worked hard and gave everything
I don't think we played bad
We were very unlucky."
The Moroccan winger rejoined Stoke earlier this month on a second season-long loan from Liverpool and came on as a late substitute against Leicester
He is playing catch-up on his fitness after missing the whole of pre-season following knee surgery
Assaidi said: "I've trained hard and I've now had one week in training with the team
In 10 minutes it's very difficult to do something but I'm happy I've got my first 10 minutes and I hope for more
"I'm very happy to be back
I know everyone here and it's easy for me
I enjoy it here."
Source : PA
Source: PA