When he was preparing for his university studies, Ladislaus's father wanted him to receive the education he would need to look after the family property. Ladislaus therefore enrolled in the faculty of agriculture at the University of Vienna, where he also studied chemistry, physics, philosophy, literature and music. It was not until 1896 that he began to study medicine in which he obtained a degree in 1900.

On 10 November 1898, he married Countess Maria Teresa Coreth, a deeply religious woman. Their marriage was a happy one and God blessed them with 13 children. The whole family took part in Holy Mass every day. After Mass Ladislaus would give the children a catechism lesson and assign to each one a concrete act of charity for that day. Every evening after they prayed the Rosary they would review the day and the assigned act of charity.

In 1902, Ladislaus opened a private hospital in Kittsee with beds for 25 patients. Here he began working as a general practitioner, later specializing as a surgeon and oculist. During the First World War, the hospital was enlarged to admit 120 wounded soldiers for treatment.

On the death of his uncle, Ödön Batthyány-Strattmann, in 1915, Ladislaus inherited the Castle of Körmend, in Hungary. He also inherited the title "Prince" and the name "Strattmann". In 1920 his family moved from Kittsee to Körmend. They turned one wing of the castle into a hospital that specialized in ophthalmology. Ladislaus became a well-known specialist in this field, both in Hungary and abroad. He was also known as a "doctor of the poor", and the poor flocked to him for assistance and advice. He treated them free of charge; as the "fee" for their medical treatment and hospital stay, he would ask them to pray an "Our Father" for him. The prescriptions for medicines were also free of charge and, in addition to providing them with medical treatment, he often gave them financial assistance.

As well as the physical health of his patients, Ladislaus was also concerned with their spiritual health. Before operating he would ask God to bless the operation. He was convinced that as the medical surgery was his domain, he was still an instrument in God's hands, and that the healing itself was a gift of God. Before his patients were discharged from hospital, he would present them with an image of Our Lord and a spiritual book entitled: "Open your eyes and see". This was a way to give them guidance in their spiritual life. He was considered a "saint" by his patients and even by his own family.

When Ladislaus was 60 years old, he was diagnosed with a tumor of the bladder. He was admitted to the Löw Sanatorium in Vienna. This was to be the greatest trial of his life. His patience and charity were unfailing. From the sanatorium he wrote the following words to his daughter, Lilli: "I do not know how long the good Lord will make me suffer. He has given me so much joy in my life and now, at the age of 60, I must also accept the difficult moments with gratitude". To his sister he said: "I am happy. I am suffering atrociously, but I love my sufferings and am consoled in knowing that I support them for Christ".

Dr Ladislaus died in Vienna on 22 January 1931 after 14 months of intense suffering. He was buried in the family tomb in Güssing. His lifelong motto had been: "In fidelity and charity".