The election was postponed in Jayanagar and Rajarajeshwari Nagar, following the death of the MLA B. N. Vijaya Kumar and a voter fraud scandal respectively till 28 May.

The Janata Dal (Secular), and the Bahujan Samaj Party (BSP) contested the election in an electoral alliance.

[8] The District Election Officer for the Bangalore region stated that a "vulnerability mapping exercise" would be conducted to ensure "free and fair polls".

[9] Voter-verified paper audit trail (VVPAT) machines were used with EVMs in all polling stations in Karnataka.

[12][13] The Election Commission of India ran into a major embarrassment on 27 March 2018, when BJP IT cell head Amit Malviya and the Karnataka Congress' social media in-charge, Srivasta, tweeted the dates before they were officially released.

[17] Om Prakash Rawat, the Chief Election Commissioner of India, formed a committee to investigate the alleged leak.

On 8 May, almost 10,000 voter ID cards, along with several laptops, were found in a flat in Bengaluru owned by former BJP leader Manjula Nanjamari.

The election was one of the hottest points considered by the critics for the future of Karnataka in dealing with the rivals, Tamil Nadu over the Kaveri River water dispute.

[28] The party spent 85 days covering all the assembly constituencies, culminating in Bangalore on 4 February 2018, with Prime Minister Narendra Modi addressing it.

[44] A poll conducted by CHS in the same month found that Kumaraswamy was the first choice, followed by Yeddyurappa and Siddaramaiah in that order.

[56] BJP under the leadership of Yeddyurappa formed the government, based on being the single largest party of the house, despite the Congress and JD(S) post-result alliance having a majority.

The Governor then gave a 15-day window for the new government to prove the majority in the legislature, which was shunned by the opposition as favoring the BJP.

The Supreme court then limited the window to 3 days and then Chief minister Yeddyurappa resigned 10 minutes before the trust vote.

16 Legislators from the ruling coalition resigned within a span of 2 days and 2 independent MLAs switched their support to BJP.

After 3 weeks of turmoil, HD Kumarasamy lost the trust vote by 100–107 in the house (held on 23 July 2019) and resigned.

The assembly elections were held across the state on 12 May, but the poll in Jayanagar was countermanded following the death of BJP candidate B N Vijayakumar, who was holding the seat.