Ali Amrozi bin Haji Nurhasyim was born on 5 July 1962 in Tenggulun, Lamongan, East Java, Indonesia. He was the fifth child among thirteen siblings in a deeply conservative Islamic household. His father, Nur Hasyim, was a religious hardliner who participated in Indonesia’s independence struggle and held strong anti-Western views. The family strictly followed Wahhabism, a puritanical branch of Sunni Islam with roots in Saudi Arabia.

Amrozi's early education took place at the Al-Mukmin Islamic boarding school, founded by radical cleric Abu Bakar Bashir. Along with his brothers Muklas and Ali Imron, he was raised in an environment that rejected Javanese cultural customs as un-Islamic. His grandfather had founded the first pesantren (Islamic boarding school) in their village, reinforcing the family’s religious reputation.

Despite this background, Amrozi showed little academic promise. He was disruptive, undisciplined, and labeled by psychiatric reports as “simple” and “shallow,” with an immature personality and below-average intelligence. He was often in trouble at school and eventually dropped out during his second year of high school.

After a failed early marriage, Amrozi became increasingly directionless. He vandalized local graves in a desperate attempt to gain approval from his father. His actions shocked the community, especially when he desecrated the grave of a respected elder, resulting in police detention.

His life took a turning point when he reconnected with his brother Muklas in Malaysia in the late 1980s. Initially rejected, Amrozi adopted stricter Islamic practices to regain acceptance. He began praying regularly, gave up smoking, and distanced himself from worldly distractions. Gradually, he earned his brother’s approval and was absorbed into the radical circles of Southeast Asian Islamist groups.

In the 1990s, Amrozi attended the Lukman Nul Hakim pesantren, where he was exposed to radical ideologies. He gained practical skills as a mechanic and was known for his talent in fixing electronics and vehicles.

Ali Amrozi became involved in organized terrorist activities as part of the Indonesian Islamist group Jemaah Islamiyah (JI), a group linked to al-Qaeda. He was involved in the planning and execution of multiple bombings, including the 2000 Christmas Eve attacks across Indonesia and, most notably, the 2002 Bali bombings.

On 12 October 2002, Amrozi helped coordinate the attack that killed 202 people, mostly foreign tourists, in Bali. The first explosion targeted Paddy's Irish Bar. The second and deadlier bomb was loaded into a Mitsubishi L300 van parked outside the Sari Club. This van, purchased and prepared by Amrozi himself, carried a massive IED. A third, smaller device exploded near the U.S. Consulate in Denpasar, but caused no injuries.

Amrozi was arrested on 5 November 2002 after police traced the van's registration back to him. During interrogation, he showed no remorse and even smiled during press conferences—earning him the notorious nickname, "The Smiling Bomber." He admitted to his involvement and later claimed responsibility for other bombings in Jakarta, Ambon, and several churches across Indonesia.

His brother Muklas, who radicalized Amrozi, was convicted as the mastermind behind the Bali bombings. Another co-conspirator, Imam Samudra, also received the death penalty. All three men were sentenced in 2003 and transferred to Nusakambangan prison after threats and unrest followed their incarceration in Bali.

Amrozi’s behavior during his trial was marked by mocking comments, laughter, and defiance. Psychological reports characterized him as immature and easily manipulated. Despite the opportunity for appeals and a potential presidential pardon, Amrozi and his co-conspirators initially refused to pursue one. They later challenged their death sentence on constitutional grounds, arguing against the method of execution. Amrozi preferred beheading over a firing squad.

The appeals were ultimately dismissed. On 9 November 2008 at 00:15 local time, Amrozi, Imam Samudra, and Muklas were executed by firing squad.