[4] Aliyu was elected in 1999 as a member of the People's Democratic Party (PDP) for the Niger North constituency and appointed chair of the Upper House committee on Police Affairs.
[7] In January 2003, as Senate Committee chairman on Security and Intelligence, Aliyu advised the house not to conduct the screening of three proposed ministers in haste and later come back and complain about the behaviour of the nominees.
[10] In January 2004, his guest house in Kontagora, Niger State was burned during riots that followed a disputed local election.
[11] In February 2004, he attended a meeting of the Niger State caucus of the Peoples Democratic Party, which issued a declaration that the creation of seventeen additional local government councils was permanent and the elections on January 10, 2004 were valid.
[13] Also in September 2004, Aliyu seconded a motion that President Olusegun Obasanjo should relieve Mallam Nasiru El-Rufai of his job as Minister of the Federal Capital Territory (FCT) within 48 hours.
[18] In February 2006, Nuhu Aliyu described the alleged third term bid of President Olusegun Obasanjo and the constitutional review as "evil.
He was appointed to committees on Security & Intelligence, Police Affairs, Local and Foreign Debts, Culture & Tourism and Communications.
[24] In March 2008, Aliyu donated 400 motorbikes and 400 sewing machines to the local government of Borgu in Niger State, to be distributed to the people.
[25] In a May 2009 interview, Aliyu said a police report presented to the Court of Appeal on the Osun State governorship election petition was forged, noted that the sole role of police in an election was to keep the peace, and expressed confidence in the evolution towards full democracy in Nigeria.