I have been meaning to review this book for years, since we used it when my son was 5 and he is now 13. The great news is that he no longer has even the slightest hint of a lisp and all it took was about one month of doing the lessons in this book 8 long years ago.His dad had a lisp when he was small, and back then the public schools used to recognize the problem and provide speech therapy. My son's lisp was very noticeable, especially because he has an 'S' in his name, but neither his preschool teachers nor his kindergarten teacher ever mentioned it. After hearing about my husband's experience I expected it to be addressed in kindergarten but even when I brought it up to the teacher myself he didn't seem very concerned.I knew I was on my own, so I bought this book and it was smooth sailing from there. The lessons were so easy it didn't feel much like work to me or my child, and he progressed so quickly we didn't even have to spend as much time on the lessons as they recommended. Very little reminding was necessary when we were done. That might not be true for everyone but for us it was a completely painless and effective process. For that reason I recommend at least trying this program before spending hundreds or thousands on speech therapy.

My three and a half year old daughter had been doing private speech therapy (at $100 an hour) for her lisp for about one month before we moved to German-speaking Switzerland. I was afraid I wouldn't be able to find a native English speaking speech therapist in Switzerland, so I bought this book before we left the U.S. We have completed this book and it went very successfully. There are three important things to know however: (1) don't be deceived by the "15 lessons" title. There are 15 chapters, but each "lesson" is followed by 2 or 3 practice sessions. You can only do one lesson or practice session a day. Overall I think there are over 50 days of lessons/practice sessions. (2) You must be motivated to do this. The sessions are not difficult, but you must be consistent in actually doing them on a fairly regular basis. I failed miserably at this at first until I decided to do speech therapy with my daugher every day immediately after dinner. She couldn't get dessert until she had finished her speech therapy. (3) Even when you are done with the 50 or so sessions, your child's speech will not be perfect yet. After we were done with the book, my daughter could correctly make the "s" sound when reminded to do it, but she couldn't always remember to do it. You have to constantly remind your child to properly pronounce the "s" sound. The better you are about correcting your child's speech the faster he/she will progress.
Overall this book was a tremendous help to our child, and well worth the purchase price.

My 7-yr-old's lisp was pretty mild, and the pace of this was very easy for him, but he enjoyed having such easy success. And it is helping. It is certainly a lot easier and cheaper than going to a speech therapist regularly!