At lunch, on the second day, England were 498 for six after Pietersen had shared a sixth-wicket stand of 160 with Matt Prior, who made 75.
Pietersen's innings leaves him with four of his eight Test hundreds being in excess of 150 - a fine conversion rate.
Such was England's dominance, West Indies pace bowlers - Daren Powell, Corey Collymore and Jerome Taylor - had all conceded more than 100 runs each.
Taking the new ball did them few favours either, with 90 runs scored for one wicket in 17 overs.
England resumed well-placed on 366 for five with Pietersen 130 not out and in sight of his previous Test best score of 158 which, curiously, he'd achieved three times.
Pietersen had been in commanding form on Friday, racing to his century in 104 balls which was the South Africa-born batsman's second Test hundred in as many innings, after his 109 in the drawn series opener at Lord's.
England's strong position had initially been built around Michael Vaughan's 103, the captain marking his return to Test action after 18 months out injured with a hundred.
Pietersen, who'd been stumped off a no-ball on 20, got going on Saturday with a leg-glanced four off Collymore.
Prior, whose 126 not out at Lord's saw him become the first England wicket-keeper to score a hundred on Test debut, then commandingly pulled Powell for four through mid-wicket.
Pietersen broke the 158 barrier when a flashing cut off Taylor raced down to the third man boundary.
Together with Prior he posted a hundred stand at a run-a-minute against an attack lacking variety and threat.
Prior then brought up his fifty in 72 balls with his sixth boundary, a square-cut, off Taylor whose first six overs on Saturday cost 36 runs.
Medium-pacer Dwayne Bravo didn't escape punishment either, Pietersen playing his trademark 'flamingo' shot to whip him from outside off-stump to the long-on boundary.
Prior's bold innings ended when he was clean bowled by a fine Powell delivery that clipped the top of off-stump. He faced 99 balls with nine fours.
West Indies who were already without senior batsman Shivnarine Chanderpaul for this match because of a right knee injury, suffered a further setback before play Saturday when captain Ramnaresh Sarwan didn't take the field.
He'd gone off late on Friday after injuring his right shoulder when tripping over the boundary rope.
Following a hospital scan, it was announced on Saturday that Sarwan would neither field in the remainder of England's first innings nor bat in the tourists' reply.
A team spokesman said more scan results would be needed before deciding if Sarwan could take any further part in this match.
Brief Scores (at lunch-D-2)
England 498 for 6 (Pietersen 189 n o, Vaughan 103, Matt Prior 75, Cook 42; Collymore 2 for 110, Powell 2 for 129, Gayle 1 for 35) Vs West Indies.