Customers dined back-to-back at this tiny eatery dubbed the 'narrowest noodle restaurant in Thailand'.

Locals were seen queueing to sample the popular noodle dishes despite the tight squeeze at the homely roadside restaurant in Phitsanulok province on October 20.

The humble hole-in-the-wall became a hit as locals praised the delicious but affordable food served in generous portions, with each hearty bowl only costing 50 THB (1.4 USD).

The sparse dining area - which is composed of two benches and two wall-mounted counters - is only a metre wide and five metres high, with a capacity of eight customers at most.

Beyond the narrow alley, the owner Narong Wantuan, 64, and his wife Suwan, 60, were hard at work manning the counter and cooking the shop's signature soups at the entrance to their home.

The couple, who had previously worked as tricycle drivers, shared with local media that they had ventured into the food business around 40 years ago, when alternative public transportation like motorcycle taxis began to flourish and cut into their income.

They said a kind friend had shared with them a noodle recipe and they have since tweaked it to become the secret to their success.

After renting space only to be repeatedly kicked out by landlords, the pair finally decided to open their noodle store on a tiny section of their property. Over the years, the restaurant became well-known and frequented by hungry residents looking for inexpensive but filling meals.

Narong said: 'Sometimes, when the dining area is full but there are many people waiting, we would even let them eat inside our house.'

Among the shop's best-selling dishes is the slow-cooked braised beef meatball noodles with flavourful bone broth. The in-demand dish is popular enough that the couple said they use up seven kilogrammes of beef daily to meet the demand.

The restaurant is open from 8 am until noon, with dine-in and takeaway options available.