A circuit which can function both as quadrature oscillator and as a universal biquad filter (low-pass, high-pass, band-pass, band-reject and all-pass functions) is introduced in this paper. Working as quadrature oscillator, the oscillation condition and oscillation frequency can be adjusted independently with the input bias currents. Functioning as a universal biquad filter, the quality factor and natural frequency can be tuned orthogonally via the input bias currents. The proposed circuit can work as either a quadrature oscillator or a universal biquad filter without changing circuit topology. The proposed circuit description is very simple, consisting of merely 2 current controlled current conveyor transconductance amplifiers (CCCCTAs) and 2 grounded capacitors. Without any external resistors and using only grounded elements, this circuit is thus suitable for IC architecture. The PSPICE simulation results are depicted, and the given results agree well with the theoretical anticipation. The maximum power consumption is approximately 3.78 mW at plusmn1.5 V power supplies.