The drinks maker said that while group sales would rise in 2017, the conflict in the Middle Eastern nation meant the supply route to the country had been blockaded and shipments planned for this month had been unable to get through.
"As a outcome, management now expects adjusted group profit before tax [PBT] for the year ending December 31 2017 to be in line with the prior year".
However, Nichols' Middle East woes are in stark contrast to sales to the United Kingdom, where Vimto sales are up over 9 per cent year on year, well ahead of the market.
The group said that the strong performance helped it mitigate rising costs linked to the weak pound following the vote to Brexit.
Going ahead, Nichols expects low single-digit profit growth in 2018 due to Yemen as well as a possible economic slowdown in Saudi Arabia which both will affect its Middle East business.
The company's global sales were expected to be up, with revenues in Africa forecast to be up 20% compared with past year. Africa is likewise expected to continue to perform well.
"For the year ahead, we are confident that the strong sales trend will continue in the United Kingdom with the Vimto brand being supported by a new marketing campaign launching in the spring".
Nichols, which sells in more than 85 countries, owns brands such as Levi Roots soft drinks, Feel Good and Sunkist.
The firm added that it is well prepared for the introduction of the Sugar Levy, with the Vimto and Feel Good brands portfolio already below the levy's threshold.