Domnern Somgiat & Boonma was established by Ina Wilhelmina Jorgensen. Born in Bangkok on 14 November 1905, Ina was the youngest of the four children of Carl and Wilhelmina Jorgensen, a Danish couple living in Thailand, which was then still known as Siam. At the age of 23 she joined the law firm of Tilleke & Gibbins as secretary to the partners, eventually becoming the Office Manager. In 1931 Thailand's first Trade Marks Act was introduced, and the firm actively engaged in handling trademark prosecution on behalf of its clients. When the Second World War broke out in 1939 and subsequently affected Thailand, the partners, all British subjects, dispersed, leaving Ina to look after the interests of the firm.

After the war ended in 1945, Brigadier Victor Henry Jaques, the last surviving partner, returned to Thailand to resume the law practice of the firm. On his retirement in 1947, he sold the name and part of the business to others and assigned the trademark side of the business to Ina, who then named it "Jorgensen & Co." At the outset, Brigadier Jaques still worked in partnership with Ina. When he died a few years later, she continued to keep the firm operating, serving clients with a small staff of about five people. The Trade Marks Act was at that time approaching its twentieth anniversary. Ina then enlisted Domnern Garden of Harvard Law School who had been admitted to the Thai Bar. He in turn brought in former Registrar of Trademarks Somgiat Sitthisiri and later Chulalongkorn Law School and Columbia Law School graduate Boonma Tejavanija. Ina retired in 1981 at the age of 76 and the firm became Domnern Somgiat & Boonma a few years later.

When Thailand's first Patents Act was introduced in 1979, the firm began practicing patent law. It employed a panel of chemists, engineers and experts from other scientific fields, most of whom were connected with a university. Through its foreign associates, it also began handling trademark and patent work outside Thailand, especially in Indo-China and other Southeast Asian countries.

Today, Domnern, as it is often called by friends and clients, has five partners consisting of four attorneys at law admitted to the Thai Bar, namely Nettaya Warncke, Rutorn Nopakun, Chakrapat Mongkolsit and Kiat Poonsombudlert, and a patent attorney with both legal and technical backgrounds, Prabjote Busdee. It has 118 full-time members (including the partners) and 76 outside experts from various technical fields with whom it consults regularly on technical issues. About 12.5% of all trademark applications filed in Thailand and 50% of patent applications filed by foreign companies in Thailand are handled by the firm. The firm also regularly handles trademark and patent work through associate firms in Vietnam, Laos, Cambodia and Myanmar (Burma).