Born on 31 December 1963, Ethuro attended secondary school at Lodwar High School from 1978 to 1981. He is an alumnus of the Alliance High School, holds an MSc degree from the Clemson University, and a BSc degree from the University of Nairobi.

Before joining Parliament, Ethuro, an ardent soccer lover and member of the Bunge FC team, served as a deputy country representative for Oxfam and as a research scientist for the Kenya Agricultural Research Institute.^{[citation needed]}

Ethuro was first elected to Parliament as the Member for Turkana Central in the 1997 General Election, and has been re-elected three times, consecutively. He served as the Assistant Minister for Planning and National Development from 1998 to 2002 under President Moi's government, an appointment that came immediately after his first election to Parliament.

Apart from the acting Speaker’s position, Ethuro featured in critical Parliamentary Select Committees of the House, top among them the Committees on the Constitution, the Budget Committee, and the Constituency Development Fund (CDF) Committee. He was among key members of Parliament that actively and successfully mid-wifed the Constitution, and served as a member of the Constitution Implementation Oversight Committee.

He has served as the chairperson of the parliamentary committee on CDF for two terms of Parliament from 2002 to 2012.

Ethuro played an active role in the Amani Forum — a Great Lakes regional parliamentary peace initiative that mobilised MPs and involved them in peace forums following the 2007 post-election violence and stalemate that came about from the presidential election result, which was disputed by ODM. As the chairman of the forum, and with the facilitation of Parliament, he convened an urgent meeting of MPs and dispatched various teams to the grassroots to preach peace, an initiative that contributed to calming down the political temperatures at the time.

He has also served as a member of the Procedures Committee, which deals with the Standing Orders of Parliament.^[2]

In 2012, Ethuro and three other members of parliament from Turkana county were summoned by the CID director to shed some light on what they knew about the murder of 41 police officers in Suguta Valley.^[3] Along with Turkana South MP Josephat Nanok, Ekwe Ethuro was charged with incitement to violence, becoming the second set of leaders to be put in the dock over the Baragoi killings. They appeared before chief magistrate Waweru Kiarie but did not plead to the charge, claiming it was a violation of their rights and an abuse of the judicial system.

The two MPs were released on a cash bail awaiting a ruling on whether to refer the matter to the High Court.^[4] The court later dismissed the incitement case against the two Members of Parliament. Chief magistrate Waweru Kiarie ruled that the charges preferred against Turkana South MP Josphat Nanok and his Turkana Central counterpart David Ekwe Ethuro were defective. Through lawyers Katwa Kigen and Jotham Arwa, the legislators claimed that the charges raised constitutional issues and asked the magistrate to suspend the plea and refer the matter to the High Court for interpretation.^[5]

The Jubilee coalition won a majority in the Senate during the 2013 general elections, with 30 seats. During his victory speech, Ethuro promised to uphold the rule of law and offer stewardship leadership. He also paid tribute to the pioneer Senators of post-independence, promising to look up to them for inspiration, guidance and advice.^[6]

Ethuro was unanimously chosen by the Jubilee coalition as their nominee for Speaker after former Speaker of Parliament Francis ole Kaparo stepped down in his favour. Ethuro won the elections for Speaker of the Senate with the backing of the Jubilee coalition, managing 38 votes against CORD's Farah Maalim's 29 votes in the second round of voting. In the first round of voting, Ethuro garnered 35 votes, which was less than the two-thirds needed for a win, while Farah got 31 votes, Omondi had one vote and there was one spoilt vote.^[7]

On 31 August 2017 Kenneth Lusaka who had lost the Bungoma county gubernatorial race (and was until then the incumbent governor) was elected speaker of the Senate. Lusaka received 42 to NASA candidate Farah Maalim 25 votes, while Ethuro received only two votes.^[8] This effectively put an end to Ethuro's term as senate speaker.