Multifunctional pillow (1) for supporting the arm in the position of the seated user, characterized in that it comprises: - a wider cylindrical segment (2) that will be located in front of the user's abdomen and resting on his knees and whose function is to support his hand and forearm. That greater width is required to prevent the hand from sliding to the side. - a narrower cylindrical segment (4), which is placed under the user's forearm, between the arm and the armrest, upwards to the top of the chair. - a point of support (3) for the elbow at the junction between the widest segment (2) and the narrowest segment (4). Said support point (3) remains sunk with respect to the surface of the rest of segment (2) and (4) so that the elbow is fitted in that support (3) and does not slip. - a zone of narrowing (5) in the unión segments (2) and (4) which is characterized because deliberately includes less filling material in that section of the pillow, so as to facilitate the twisting between the two segments to achieve the appropriate angle of the multifunctional pillow according to the needs of the user. - at the end of the narrowest segment (4), there is a non-extensible flexible ribbon in the form of coca (6) (using the term of nautical knots) whose function is to secure that segment to the upper part of the backrest. As normally this multifunctional pillow will be used in a wheelchair, said coca would be passed through the pushing handle of the wheelchair and thus the narrowest segment (4) is held in a vertical position. - a tape (1) that is characterized by being flexible and non-extensible, whose function is to keep the wider segment (2) next to the abdomen of the user. Said belt (7) is characterized in that it is joined by means of a clip (8) at one end to the wider cylindrical segment (2), its central part runs through the back part of the backrest of the wheelchair, and at the other end it goes stitched to the end of the narrowest segment (4). - an adherent surfa