Doukara struck his third goal in four games in the 59th minute to settle a lacklustre contest, enlivened by some intricate footwork from City's own Frenchman Jonathan Kodija.
Chris Wood returned to the Leeds bench after a four-match absence with a hamstring injury and his introduction nine minutes into the second half sparked an improvement.
Ben Gladwin, signed on loan from QPR this week, made his debut for Bristol but Alex Pearce, on loan from Derby, had to wait until the start of the second half to replace Nathan Baker.
Interim manager John Pemberton, the former Leeds defender, was looking for more league success after City's 1-0 win against Middlesbrough last weekend but apart from Kodija's contribution the first half was almost totally devoid of thrills.
England Under-21 international Baker was fortunate to avoid a card for a cynical late tackle on Leeds midfielder Luke Murphy who was the victim of another trip soon afterwards, but Leeds wasted the resultant free-kicks.
City gave the Leeds crowd a 25th-minute scare when Liam Bridcutt lost possession on his own goal-line and Baker stung Marco Silvestri's hands with a rasping shot from a narrow angle.
Leeds badly needed to increase the tempo but a mixture of their own mistakes and a couple of over-robust tackles, which earned bookings for Baker and Kodija, did nothing to boost the game's entertainment value.
Kodija was an exception to the general lack of quality.
The Frenchman proved a handful for the Leeds defence and City's top scorer headed fractionally wide with Silvestri failing to move a muscle. The lively Kodija then cleverly ghosted past two Leeds defenders inside the penalty box before having his low shot blocked by Silvestri.
The interval arrived goalless and both sides' supporters voiced their disapproval.
Leeds hopes rose when their eight-goal top scorer Wood left the bench in place of the ineffective Mustapha Carayol in the 54th minute and five minutes later they were ahead.
Stuart Dallas raided down the right and his low cross cannoned off Wood to Doukara who fired the ball past Richard O'Donnell from close to the penalty spot.
City should have equalised in the 79th minute but Aden Flint somehow contrived to head wide from six yards unchallenged.
Leeds sent on Mirco Antenucci with four minutes left, as they sought to increase their advantage, but the Italian was immediately involved in an altercation with Luke Ayling and Steve Evans' men had to be content with Doukara's earlier effort.
Read more: http://www.dailymail.co.uk/sport/football/article-3413500/Leeds-United-1-0-Bristol-City-Souleymane-Doukara-settles-contest-Elland-Road.html#ixzz3yB2TBLgk
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