The company posted a loss of $8.9m (£6.1m) for the period, down from a profit of $52.5m in the same three months last year.
Global revenue climbed 5.5 per cent to $203.8m on the back of strong sales of Dunkin branded k-cup pods for home coffee machines.
Over the last three months same store sales at Dunkin' Donuts dropped almost one per cent in the US.
In October last year the company hiked prices at its franchisees by three per cent to offset slipping sales and the impact of a rise in minimum wages.
Chief executive Nigel Travis branded the fall in sales as “disappointing”, and said he will be bringing in offers to drive sales.
Travis said: “To help drive positive Dunkin' Donuts transactions in 2016 and the years beyond, we have begun executing against a strategic plan designed to enable us to deliver an even better guest experience through stronger product innovation, leading technologies to enhance convenience such as on-the-go mobile ordering, and targeted, compelling value offers."
The firm has seen an increase in competition in the breakfast food market recently, as McDonald's has opened up its breakfast menu to throughout the day.
Rivals Wendy's and Burger King have also upped their number of limited time offers that have dented sales.
The US-listed firm is aiming to open 150 outlets in the UK by 2018, and did a franchise deal with US operator DDMG to open 25 branches in north London in 2013.
Same-store sales at Baskin-Robbins in the US also took a beating, growing by just 4.4 per cent, down from 9.4 per cent during the same period a year ago.
The company put the continued growth down to strong demand online.