Women turned out in strength in the rural areas of the Hamirpur and Kangra parliamentary constituencies.
There were minor hiccups as electronic voting machines developed snags at some places.
Chief Minister Jai Ram Thakur, two-time former Chief Minister Prem Kumar Dhumal and former Union Minister and Congress leader Anand Sharma were among the early voters in the state.
"There has been no report of any major delay in starting the poll process," Chief Electoral Officer Devesh Kumar told here.
The main contest is between the Congress and the Bharatiya Janata Party (BJP).
Forty-five candidates, comprising lone woman, are in the fray for the four seats Shimla (reserved), Kangra, Mandi and Hamirpur.
With the electorate, traditionally in the Lok Sabha polls, favouring the party at the helm in the state, these elections are being seen as a referendum on state's 17-month-old BJP government.
The BJP wrested the state from the Congress in December 2017, winning 44 seats in the 68-member Assembly. The Congress won 21 seats, Independents two and the Communist Party of India-Marxist one.
While in Mandi, Kangra and Shimla, it's about steering his party to victory, in Hamirpur it's a battle of supremacy between the Chief Minister and his predecessor Dhumal, who has almost been marginalised in state politics after a humiliating defeat in the 2017 Assembly polls.
From Kangra, the largest Lok Sabha constituency in the state in terms of voters, the BJP has fielded Cabinet Minister Kishan Kapoor, 68, after dropping veteran leader Shanta Kumar, against Congress two-time legislator Pawan Kajal, 44.
In the Shimla (reserved) seat, it is an ex-serviceman versus an ex-serviceman. Retired Colonel Dhani Ram Shandil, 78, is the Congress candidate against Bharatiya Janata Party nominee and former Indian Air Force (IAF) officer Suresh Kashyap, 48.
In Hamirpur, Dhumal is trying to ensure a fourth term for his son Anurag Thakur, former president state and national cricket bodies. Pitted against Anurag Thakur, 44, is ex-wrestler and five-time Congress legislator Ram Lal Thakur.
Sitting BJP MP and the Chief Minister's confidante Ram Swaroop Sharma is seeking a second term from Mandi. He is contesting against Congress greenhorn Ashray Sharma, who is the grandson of former Telecom Minister Sukh Ram.
Sukh Ram, a Congress veteran joined the BJP just before the Assembly elections, but defected back after his grandson was denied a ticket.
Ashray's father Anil Sharma still remains in the saffron party and though he has not campaigned either for his son or for his party in these elections, his father is more than making up for it.