Moving to the Malaysian capital Kuala Lumpur, Lat applied for a cartoonist's position at Berita Harian. He was told there was no vacancy, but the paper's editor, Abdul Samad Ismail, offered him the post of a crime reporter. Lat accepted, a decision he explained was borne from necessity rather than choice: "It was a question of survival. I had to earn money to help support the family." At that time, Lat's father had fallen seriously ill and could not work; Lat had to become the breadwinner of his family. Aside from taking the job, he continued contributing cartoons to other publications. Lat was later transferred to Berita Harian's parent publication, New Straits Times. Moving throughout the city to report on crimes gave Lat opportunities to observe and interact with the myriads of lives in the urban landscape, enabling him to gather material for his cartoons and increasing his understanding of the world. Nevertheless, he felt he lacked the persistently inquisitive nature needed to succeed as a crime reporter. Furthermore, his "breathtakingly detailed, lurid and graphically gory descriptions" of the aftermaths of crimes had to be frequently toned down by his seniors. Lat became convinced that he was a failure at his job, and his despondency led him to tender his resignation. Samad, believing Lat had a bright future with the press, furiously rejected the letter.

In 1981, Town Boy was published. It continued The Kampung Boy's story, telling of the protagonist's teenage life in an urban setting. Two more compilations of Lat's editorial cartoons (With a Little Bit of Lat and Lots More Lat) were published and the number of people who recognised him continued to grow. In 1984, partly from a desire to step away from the limelight, Lat resigned from the New Straits Times to become a freelancer, but continued to draw Scenes of Malaysian Life for the newspaper. He set up his own company, Kampung Boy Sendirian Berhad (Village Boy private limited), to oversee the merchandising of his cartoon characters and publishing of his books. In 2009, Kampung Boy partnered Sanrio and Hit Entertainment in a project to open an indoor theme park which would later be called as Puteri Harbour Family Theme Park in Nusajaya, Johor in August 2012.] One of the park's attractions will be the sight of performers dressed up as Kampung Boy characters beside those in Hello Kitty and Bob the Builder costumes and also reported in August 2012 will be a Lat-inspired diner called Lat's Place. It will be designed in a Malaysian village setting, coupled with animations for patrons to interact with.

At the time that Lat started drawing for the New Straits Times, local political cartoonists were gentle in their treatment of Malaysian politicians; the politicians' features were recreated faithfully and criticisms were voiced in the form of subtle poems. Lat, however, pushed the boundaries; although he portrayed the politicians with dignity, he exaggerated notable features of their appearances and traits. Lat recalled that in 1974, he was told to change one of his works, which portrayed Malaysian Prime Minister Abdul Razak from the back. Lee refused to print the work unchanged, and pointedly asked the cartoonist "You want to go to jail?!" In 1975, however, Lat's next attempt at a political cartoon won Lee's approval. The satire featured a caricature of Razak's successor—Hussein Onn—on the back of a camel, travelling back to Kuala Lumpur from Saudi Arabia; its punchline was Hussein's hailing of his mount to slow down after reading news that a pay raise for the civil service would be enacted on his return.

Music has played a crucial part in Lat's life since his youth; he revealed in an interview that listening to songs such as Peggy March's "I Will Follow Him" and Paul & Paula's "Hey Paula" helped him learn English. Listening to music had also become an important ritual in his work, providing him with inspiration in his art. When he sketches "fashionable girls", he puts on Paul McCartney's tracks, and switches to Indonesian gamelan when he needs to draw intricate details.He enjoys pop music, particularly rock music of the 1950s and 60s listening to The Beatles, Bob Dylan, and Elvis Presley. Lat is also partial to country music, and to singers such as Hank Williams and Roy Rogers because he finds their tunes "humble" His enjoyment of music is more than a passive interest; he is proficient with the guitar and piano, and can play them by ear.