In this Letter, we propose a novel triplex-parameter detection method to realize simultaneous radiometric, photoacoustic, and ultrasonic imaging based on single-pulse excitation. The optical attenuation, optical absorption, and acoustic impedance properties can be obtained simultaneously by analyzing the photoacoustic signals and the ultrasonic echo signals. To test the feasibility and accuracy of this method, agar phantoms with different absorption coefficients and elastic coefficients were measured. Then, this method was experimentally verified by imaging a leaf skeleton piece embedded in an agar cylinder. Furthermore, pilot experiments were performed by triplex imaging of pig ear tissue ex vivo to characterize the cartilage and surrounding tissue. Experimental results demonstrated that this technique has future potentials for visualizing and providing the functional and structural information of biological tissues.