International Friendly: Chile 5 Venezuela 0
The 31-year-old attacking midfielder, who retired after the World Cup, marked his return with a goal at the Estadio CAP in Talcahuano.
Alexis Sanchez and Valdivia scored in the first half and Eduardo Vargas, Rodrigo Millar and Pablo Hernandez netted in the second as Jorge Sampaoli's men eased to victory.
Venezuela are still winless under Noel Sanvicente, who took over as coach in July, but they did have some bright moments.
The visitors had a glorious chance to take the lead in just the second minute, with Mario Rondon forcing Claudio Bravo into a low save in a one-on-one.
Chile enjoyed the majority of possession and took a deserved lead in the 17th minute.
Arturo Vidal was released down the right and crossed to the back post, where Eugenio Mena squared with a volley.
And the in-form Sanchez, who has scored regularly for Arsenal, was on hand to nod in from close range and make it 1-0.
Rondon was unlucky to have a penalty shout turned down soon after before Nicolas Fedor fired a long-range effort over the bar in the 25th minute.
Valdivia shot straight at Venezuela goalkeeper Daniel Hernandez before doubling Chile's lead in the first minute of additional time.
The attacking midfielder was released down the left side of the area before his cross-cum-shot caught out Daniel Hernandez, hit the back post and crossed the line.
Chile started the second half brightly and almost made it three in the 52nd minute as Vidal's curling 20-yard effort crashed against the post after a look-away Valdivia pass.
Venezuela also hit the post moments later as Oswaldo Vizcarrondo's header bounced off the woodwork before Bravo denied Rondon.
Chile did make it 3-0 in the 55th minute with a fine team move ending in Vargas scoring.
Valdivia released Mauricio Isla with a wonderful pass and the full-back's cutback was put away into an open goal by Vargas.
Vargas hammered a shot off the post in the 72nd minute before Chile scored again soon after.
Millar was on hand to tuck away a rebound after he had played through Sanchez, whose shot was well-saved by Daniel Hernandez.
The rout was completed in the 93rd minute as Isla and Millar exchanged passes before the former crossed for Pablo Hernandez to head in.