Both series are made by cable network AMC, but Mad Men's new $10 million (£6.1m)-per-season budget could cause cutbacks on its sister shows, according to the Los Angeles Times.
The new budget for the '60s-set period drama is believed to be a condition of Mad Men creator Matthew Weiner's new deal with AMC, which guaranteed at least two more seasons of the show.
Under the new deal, The Walking Dead is expected to lose around $250,000 (£153,129) per episode, compared to its first season. The zombie drama's showrunner Frank Darabont stepped down last week, with the budget cuts being rumoured as one of the reasons for his departure.
However, AMC president Charlie Collier denied that the cost of Mad Men was having a negative impact on the network's other shows.
"We're investing more than we ever have before," he insisted. "The fact that future seasons of Mad Men were going to be expensive is not a surprise to us. We've taken some of the most expensive, riskiest shows around and nurtured them and managed to grow our network."
Collier also dismissed the suggestion that a decreased budget could be damaging for The Walking Dead.
"The viewer will see we're making shows that will look like a movie every week," he claimed.
Earlier this week, it was reported that the producers of Breaking Bad were considering taking the show to other networks, following's AMC suggestion that the show's fifth season comprise of just six to eight episodes for financial reasons.
> Mad Men season 5 to shoot next month
> Walking Dead stars: 'It gets more bloody and monster-filled'
> Breaking Bad to return for two final seasons?
Watch the trailer for season two of The Walking Dead below: