The v(4) band of trans-d(2)-ethylene (trans-C2H2D2) has been recorded with an unapodized resolution of 0.0063 cm(-1) in the frequency range of 870-1100 cm(-1) by Fourier transform infrared (FTIR) spectroscopy using a Bruker IFS 125R spectrometer.. In the analysis of the band, no indications for perturbation were found. By fitting a total of 2121 infrared transitions Of v(4) with a standard deviation of 0.00058 cm(-1) using a Watson's A-reduced Hamiltonian in the I-r representation, a set of accurate rovibrational constants up to four sextic terms for the v(4) = 1 State was derived. The v(4) band is a C type with a band centre at 987.753336 0.000039 cm(-1). (c) 2005 Elsevier B.V. All rights reserved.