A cikin shekara ta 1973, Olmert da shekarunsa ya kai 28 da haihuwa kawai ya zama wani dan majalisar dokokin kasar, ta haka ya fara sa hannu a cikin harkokin siyasa na kasar Isra'ila. A cikin shekara ta 1988, ya zama minista maras riko a cikin gwamnatin da firayim minista Shamil ke shugabanta, kuma a cikin shekara ta 1990, ya zama ministan kiwon lafiya na kasar. Daga shekara ta 1993 zuwa shekara ta 2003, shi ne magajin birnin Kudus. A cikin shekara ta 1999, ya taba yin takara tare da Mr. Sharon domin zaman shugaban rukunin Likud, amma ya fadi. A shekara ta 2003, Olmert ya zaman ministan masana'antu da cinikayya kuma mataimakin firayim ministan gwamnatin kasar Isra'ila da Sharon ya shugabanta. A watan Agusta na shekara ta 2005, bayan da Netaniyahu ya yi murabus daga mukaminsa na ministan kudi na kasar, Olmert ya maye gurbinsa.

A cikin dogon lokaci, ana ganin cewa, Olmert abokin arziki ne na Sharon a cikin rukunin Likud, kuma har kullum yana tsayawa kan goyon bayan shirin daukar matakan kashi kai da Sharon ya gabatar. Sabo da kasancewar sabani mai tsanani a cikin rukunin Likud, a watan Nuwamba na shekara ta 2005, Sharon ya kafa wata sabuwar jam'iyya,wato jam'iyyar Kadima ta Isra'ila, daga baya kuma Olmert ya shiga jam'iyyar. A ran 4 ga watan Janairu na shekarar da muke ciki, an kwantar da Sharon a asibiti a sakamakon ciwon feshewar hanyoyin jini a kwakwalwa, sabo da haka Olmert ya zama mukaddashin firayim ministan kasar. Daga baya kuma, a hukunce ne aka zabe shi da ya zama shugaban wucin gadi na jam'iyyar Kadima domin maye gurbin Sharon wajen gudanar da harkokin jam'iyyar, bugu da kari kuma an gabatar da shi da ya zama dan takara na jam'iyyar kan neman cin zaben firayim ministan kasar.