After completing his studies in 1946, Sambanthan returned to Malaya to take over the family business and continue his father’s passion for improving the plight of estate workers who suffered from illiteracy and poverty.
Eight years later, in 1954, he set up the Mahatma Gandhi Tamil School in Sungei Siput, Perak. He also lobbied for the introduction of the English language medium in Tamil schools in Perak and transformation of the South Indian Immigration Labour Fund into an education fund to assist children of plantation workers.