Oxford stretched their unbeaten run to seven matches but were left frustrated by an uncompromising Rushden.
Tommy Mooney went close with two long-range shots and had an angled header saved by keeper Billy Turley seven minutes from time.
Kevin Braniff went closest for the visitors first with a volley on the turn and then with a fierce drive.
But Rushden's injury problems increased when Gary Mills was stretchered off with a dislocated ankle.
Oxford Utd: Tardif, Mackay, Parker, Ashton, Molyneaux (Woozley 88), Basham, Wolleaston, Hand, Robinson (Winters 58), Mooney, Alsop (Davies 72).
Subs Not Used: Cox, Wanless.
Booked: Hand, Alsop, Mooney.
Rushden & D'monds: Turley, Connelly, Hawkins, Allen, Gulliver, Bell, Mills (Dempster 27), Gray, Dove, Hay, Braniff (Taylor 69).
Subs Not Used: Sambrook, Worgan, Kelly.
Ref: R Booth (Nottinghamshire).