The brightness variability of T Tauri stars is manifested in the emission lines. Both line fluxes and line profiles are variable on a vast range of time scales. The results that certain parts of the Balmer line profiles show periodic brightness variations as well as irregular variations on time scales shorter than one hour suggest that the line emission arises in a small region, locked to the stellar rotation. Another noticeable property of the profile variations is that for lines with blue shifted wind absorption, the time scale of variability in the wind component is much longer than for the rest of the line profile. This suggest different origins of the absorbing and the emitting gas. For this reason, several T Tauri stars have been monitored both at high spectral resolution using the SOFIN spectrograph at NOT, and simultaneously photometrically with the Swedish 60cm reflector on La Palma.