The service, available from an initial 300 stores, costs £2 from Monday to Thursday and £3 on Friday and Saturday, covering the cost of a staff member selecting and bagging the items in the order.
There is also be a free service offered on orders over £40 for customers signed up to the Amazon Prime-style Delivery Saver scheme. People using the service will need to order before 1pm in order to pick up after 4pm in one of two slots: 4-6pm or 6-8pm.
A Tesco spokesperson said: "We know time is valuable to our customers and they expect more convenience and choice than ever before in how, when and where they do their grocery shopping.
"Our same day grocery means our customers can get their shopping at a time and location that is convenient for them."
The service launched with a new ad from Bartle Bogle Hegarty, once again starring Ruth Jones and Ben Miller, which debuted yesterday.
Keeping up with the pack
The move will allow the UK’s largest supermarket to keep pace with its nearest rival, Sainsbury’s, which is acquiring Argos in order to boost its own collection and delivery capabilities.
It will also been seen as an attempt to hold of the threat of Amazon, which launched its own grocery delivery service, Amazon Fresh, in the UK earlier this year.
Research from Nielsen released in June found that Tesco was the retailer that stood to lose the most from Amazon’s entry to the market.
When Tesco chief executive Dave Lewis was asked in March if he saw Amazon as a threat, however, he dismissed the suggestion, saying: "Bring it on."