During a special session, broadcast live on state television, Sissi’s swearing in front of members of parliament and the government was greeted with 21 gun salute.
In March, the 63-year-old former military chief won 97 percent of the vote in a grotesquely rigged presidential election.
The election featured only one other candidate, himself an ardent Sisi supporter, after all serious opposition contenders halted their campaigns in January. The main challenger was arrested and his campaign manager beaten up, while other hopefuls pulled out, citing intimidation.
He overthrew Mohamed Morsi , Egypt’s first freely-elected president in 2013 and the first free and democratically elected civilian president of the country was sent to prison by a military coup d'etat.
Sisi was elected to his first four-year term as president a year later.
Rights groups say Egypt’s human and civil rights record has deteriorated under Sisi, but his supporters claim his tough security policy is needed to ensure stability as Egypt recovers from years of political chaos and tackles economic challenges and an insurgency.
European Union on Wednesday voiced concern over increasing number of arrests of human rights defenders and political activists in Egypt.
In a statement, European External Action Service emphasized that respect for human rights and fundamental freedoms can ensure sustainable stability and security.