Exhibit 99.1 MG MACIAS GINI & COMPANY LLP 3000 S Street, Ste. 300 Sacramento, California 95816 915-928-4600 Phone 916-928-2755 Fax August 15, 2005 Ramesh C. Trivedi, President & CEO Charles J. Novak, CFO Integrated Surgical Systems, Inc. and Subsidiaries 1850 Research Park Drive Davis, Ca 95616 Dear Sirs: Effective August 15, 2005, we can no longer service your account. We have come to this decision with great reluctance. We are resigning because we have a conflict of interest between you and our other clients. We wish to remind you that we will not be performing any services for you after August 15, 2005, and that there may be tax returns, elections, or other compliance matters for which you are now responsible. We recommend that you immediately obtain a new accountant, and we will fully cooperate in providing information to your new accountant. In addition, we require the return of the written authorization below, signed by you, to release any information to your new accounting firm. Without your written authorization, we are prohibited by our professional code of conduct from disclosing or discussing confidential client matters with anyone outside our firm. We appreciate the opportunity to have served you in previous years, and wish you success in your future pursuits. Sincerely, /s/ Jan Rosati Jam Rosati Partner Authorization to release information to new accountant: I authorize Macias, Gini & Company to respond fully to any inquiries from our successor accountant, ___________________ regarding my business tax or accounting records. - --------------------------------- ------------------------------ Signature Date - --------------------------------- ------------------------------- Signature Date