The author of this list, Reurt C. Gisolf living in Oostwoud, The Netherlands (email-adresses: rcgisolf@nexite.nl and rcgisolf@euronet.nl ) is playing viola. He was an amateur member of a pianoquartet for many, many years. This quartet made, when starting, a vow that it will never perform in public. It is just playing sightreading for the fun of the music and of the playing with each other, and to explore the litterature for this combination. The author took the task to provide the quartet with fresh music. This was the beginning of his collection of pianoquartets and of this list. The lists String Quintets and "Trout-combination with double-bass followed in the wake of the pianoquartet. There is also a list "Quartet plus". On this list are all thinkable combinations of a pianoquartet with any other instrument. This list contains only a limited number of pieces to illustrate all possibles combinations containing a pianoquartet. It is by far not complete, as it is not meant to be. On the list "Composers" there are - November 2018 - 2.400 pianoquartets mentioned, 2.250 piano-(string-)quintets and 200 quintets in trout-Combination. In most cases I have also mentioned the dates of the composers and of the piece, the nationality and a clue to the whereabouts of the notes by mentioning a publisher, imslp Petrucci to download scores and parts, a National Music Information Centre, a personal website of the composer or an online music shop. On the list Publishers you will find your way to connect with these instances. If possible, a link to them is indicated. On this site it is mainly about the notes. You will not find any audiopresentations. CD's are mentionned, if they are the only place where a special quartet or quintet is indicated. I'am busy to find for each composer a curriculum vitae. Nearly all the mentioned c.v.'s are from the Wikipedia Encyclopaedia, some from official or personal websites. Otherwise the copywrights are mentioned or a link makes clear were the material comes from. As far as possible there is for each composer a nationality indicated. You can make a choice between Quartets or Quintets or Quintets with Double Bass and in the middle of the main page you can choose a nationality; under the white letters of the alphabet you will find the composers from the indicated nationality whose familyname starts with this letter. Of course many composers should be listed under two different nationalities. Because of technical restrictons I had to make every time a choice. These is made arbitrarily. In the curriculum vitae of the composer are his or her personal circumstances more fully explained. To list all known quartets and quintets with piano is one thing, to give the interested reader insight in what he might wish to play or hear is another topic. So it seems important to show the interested reader along. I started with the quartets from France. I dedicated a whole section in mentionning and discussing the known french pianoquartets. I was barely scrachting the surface. So I altered my plans. The composers are still listed alphabetically, but now they are also grouped after their nationality. The interested reader can find for each country the pianoquartets or pianoquintets that originate from it. It will be a good thing if an interested player can find some hints about works he can chooses to play or to listen to: the more accesible scores, the very rewarding ones and so on. I can direct the interested reader to the last item of this introduction "Required skills", where I make some remarks on this subject. Nearly two thousand five hundredpianoquartets and a fast growing number of pianoquintets is a lot, but the lists are by far not complete. At the end of 2013 I have listed 1.000 pianoquintets and in the end of 2016 another thousand. May I ask every composer or interested person to mail the data of a quartet or quintet not yet listed? Especially to update an inventory is difficult, so my request is just to the composers who have just finished a pianoquartet or quintet to send me his or her name, the name of the work, and where interested people can find the notes.