Exhibit 99.1

ASX/MEDIA RELEASE

13 September 2005

pSivida to present at ThinkEquity Partners
Conference in San Francisco

Global nanotechnology company pSivida Limited (ASX:PSD, NASDAQ:PSDV, Xetra:PSI) is pleased to announce that Managing Director, Mr Gavin Rezos will present a corporate overview to potential investors at the ThinkEquity Partners Third Annual Growth Conference on Wednesday, September 14, 2005. The conference will highlight 200 of the fastest-growing, most-innovative companies in the world.

pSivida is committed to the biomedical sector and the development of products in healthcare. The company’s focus is the development and commercialisation of a modified form of silicon (porosified or nano-structured silicon) known as BioSilicon™. As a new and exciting biocompatible material, BioSilicon™ offers multiple potential applications across the high growth healthcare sector, including controlled release drug delivery, targeted cancer therapies (including brachytherapy and localized chemotherapy), tissue engineering and orthopedics. Potential diagnostics applications are being developed through its subsidiary AION Diagnostics Limited.

pSivida owns the intellectual property rights to BioSilicon™ for use in or on humans and animals. The IP portfolio consists of 26 patent families, 31 granted patents and over 80 patent applications. The core patent, which recognises BioSilicon™ as a biomaterial was granted in the UK in 2000 and in the US in 2001.

pSivida Limited is currently in negotiations to acquire a US based drug delivery company with the potential to create a global drug delivery company specializing in nanotechnology, with revenues from existing products and generating long-term value through its diversified late-stage product portfolio.

ThinkEquity Partners LLC is a research-centric institutional investment firm focused on the growth economy. ThinkEquity Partners LLC is dedicated to providing focused insight, advisory services, and capital to institutional investors and corporate constituents in the knowledge economy's key growth verticals, including technology, healthcare, media and consumer business services. For more information about ThinkEquity Partners LLC, please visit www.thinkequity.com. Member NASD and SIPC.

-ENDS-

Released by:

pSivida Limited Brian Leedman Investor Relations pSivida Limited Tel: + 61 8 9226 5099 brianl@psivida.com US Public Relations Beverley Jedynak President Martin E. Janis & Company, Inc Tel: +1 (312) 9 1100 ext. 12 bjedynak@janispr.com UK & Europe Public Relations Mark Swallow / Helena Podd Citigate Dewe Rogerson Tel: +44 (0)20 7638 9571 mark.swallow@citigatedr.co.uk

NOTES TO EDITORS:

pSivida is listed on NASDAQ (PSDV), the Australian Stock Exchange (PSD) and in Germany on the Frankfurt Stock Exchange on the XETRA system (German Symbol: PSI. Securities Code (WKN) 358705). pSivida’s shares also trade in the United Kingdom on the OFEX International Market Service (IMS) under the ticker symbol PSD. pSivida is a founding member of the NASDAQ Health Care Index and the Merrill Lynch Nanotechnology Index.

The Company’s strategic partner and largest shareholder is the QinetiQ group, the largest science and technology company in Europe. QinetiQ is the former UK government Defence Evaluation Research Agency and was instrumental in discovering BioSilicon™. pSivida enjoys a strong relationship with QinetiQ having access to its cutting edge research and development facilities. For more information on QinetiQ visit www.qinetiq.com.

For more information, visit www.psivida.com

This document contains forward-looking statements that involve risks and uncertainties. Although we believe that the expectations reflected in such forward-looking statements are reasonable at this time, we can give no assurance that such expectations will prove to be correct. Given these uncertainties, readers are cautioned not to place undue reliance on such forward-looking statements. Actual results could differ materially from those anticipated in these forward-looking statements due to many important factors including: our failure to develop applications for BioSilicon^TM due to regulatory, scientific or other issues. Other reasons are contained in cautionary statements in the Registration Statement on Form 20-F filed with the U.S. Securities and Exchange Commission, including, without limitation, under Item 3.D, "Risk Factors" therein. We do not undertake to update any oral or written forward-looking statements that may be made by or on behalf of pSivida.