Rolph, critical of the facilities at home in Newcastle after failing to reach the 200m individual medley on Monday, clocked 55.77 seconds for third place in her heat.
The 22-year-old will be joined in the semi-finals later on Wednesday by team-mate Pickering who finished 13th overall in 56.08.
But neither swimmer is considered a serious contender to win a first medal in the pool for a beleaguered British team that has not had much to shout about in Sydney.
Holland's Olympic 100m butterfly champion Inge de Bruijn qualified with the fastest time of 54.77.
"It felt a lot better today," said Rolph.
The reigning Commonwealth and former European champion in the 100m freestyle believes the presence of American Jenny Thompson in the heat helped her.
"I like to be next to Jenny," added Rolph, who has beaten the former world record holder in the past.
"We have competed a lot together in the last few years and I have been quite successful against her. Perhaps it's a psychological thing."
Backstrokers Adam Ruckwood and Simon Militis bowed out in a heat that saw Lenny Krayzelburg of the US break the eight-year-old Olympic record for the 200m distance by 0.27 secs with victory in 1:58.20.
Ruckwood was fifth (2:01.00) and Militis (2:01.20) one place further back as they finished 18th and 19th overall.
Another Olympic record fell in the 200m breaststroke where Hungary's Agnes Kovacs took half-a-second off the mark set in 1996 by South Africa's Penny Heyns who trailed home seventh in the lane alongside her.
Kovacs clocked 2:24.92 while Britain's Jaime King saw her campaign ended at the first hurdle with a time of 2:33.10 for 23rd spot overall.
Britain's 4x200m freestyle relay quartet of Claire Huddart, Karen Legg, Nicola Jackson and Janine Belton sliced just over 0.5 secs off the year-old national record.
The foursome clocked 8:07.41 to grab the eighth place in the final.
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